Windows QPA: Further cleanup of pre-Win10 code

Mostly a removal of dynamically loaded Win32 APIs.
Since Qt 6's minimum supported platform is Win10 1809
(10.0.17763, code name RS5), all these functions will
be available and no need to resolve them at run-time.

Things not remove:
WinTab functions in "qwindowstabletsupport.cpp".
Not my familiar area, so not touch it.

Pick-to: 6.2
Task-number: QTBUG-84432
Change-Id: I7ad6c3bc8376f6c0e3ac90f34e22f7628efeb694
Reviewed-by: André de la Rocha <andre.rocha@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

14 files changed, 109 insertions, 383 deletions

diff --git a/src/plugins/platforms/direct2d/CMakeLists.txt b/src/plugins/platforms/direct2d/CMakeLists.txt
index e87d2886d8..b88ac617aa 100644
--- a/src/plugins/platforms/direct2d/CMakeLists.txt
+++ b/src/plugins/platforms/direct2d/CMakeLists.txt
@@ -72,6 +72,10 @@ qt_internal_add_plugin(QWindowsDirect2DIntegrationPlugin
         winmm
         winspool
         wtsapi32
+        shcore
+        comdlg32
+        d3d9
+        runtimeobject
 )
 
 # Resources:
diff --git a/src/plugins/platforms/windows/CMakeLists.txt b/src/plugins/platforms/windows/CMakeLists.txt
index 880fa79ef5..d71d7e547f 100644
--- a/src/plugins/platforms/windows/CMakeLists.txt
+++ b/src/plugins/platforms/windows/CMakeLists.txt
@@ -59,6 +59,10 @@ qt_internal_add_plugin(QWindowsIntegrationPlugin
         winmm
         winspool
         wtsapi32
+        shcore
+        comdlg32
+        d3d9
+        runtimeobject
 )
 
 # Resources:
diff --git a/src/plugins/platforms/windows/qwin10helpers.cpp b/src/plugins/platforms/windows/qwin10helpers.cpp
index b8e834d54f..589311a902 100644
--- a/src/plugins/platforms/windows/qwin10helpers.cpp
+++ b/src/plugins/platforms/windows/qwin10helpers.cpp
@@ -40,8 +40,8 @@
 #include "qwin10helpers.h"
 
 #include <QtCore/qdebug.h>
-#include <QtCore/qoperatingsystemversion.h>
-#include <QtCore/private/qsystemlibrary_p.h>
+#include <winstring.h>
+#include <roapi.h>
 
 #if defined(Q_CC_MINGW) || defined(Q_CC_CLANG)
 #  define HAS_UI_VIEW_SETTINGS_INTEROP
@@ -96,56 +96,23 @@ public:
 
 QT_BEGIN_NAMESPACE
 
-// Starting from Windows 10
-struct QWindowsComBaseDLL
-{
-    bool init();
-    bool isValid() const
-    {
-        return roGetActivationFactory != nullptr && windowsCreateStringReference != nullptr;
-    }
-
-    typedef HRESULT (WINAPI *RoGetActivationFactory)(HSTRING, REFIID, void **);
-    typedef HRESULT (WINAPI *WindowsCreateStringReference)(PCWSTR, UINT32, HSTRING_HEADER *, HSTRING *);
-
-    RoGetActivationFactory roGetActivationFactory = nullptr;
-    WindowsCreateStringReference windowsCreateStringReference = nullptr;
-};
-
-static QWindowsComBaseDLL baseComDll;
-
-bool QWindowsComBaseDLL::init()
-{
-    if (QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows10 && !isValid()) {
-        QSystemLibrary library(QStringLiteral("combase"));
-        roGetActivationFactory =
-            reinterpret_cast<RoGetActivationFactory>(library.resolve("RoGetActivationFactory"));
-        windowsCreateStringReference =
-            reinterpret_cast<WindowsCreateStringReference>(library.resolve("WindowsCreateStringReference"));
-    }
-    return isValid();
-}
-
 // Return tablet mode, note: Does not work for GetDesktopWindow().
 bool qt_windowsIsTabletMode(HWND hwnd)
 {
     bool result = false;
 
-    if (!baseComDll.init())
-        return false;
-
     const wchar_t uiViewSettingsId[] = L"Windows.UI.ViewManagement.UIViewSettings";
     HSTRING_HEADER uiViewSettingsIdRefHeader;
     HSTRING uiViewSettingsIdHs = nullptr;
     const auto uiViewSettingsIdLen = UINT32(sizeof(uiViewSettingsId) / sizeof(uiViewSettingsId[0]) - 1);
-    if (FAILED(baseComDll.windowsCreateStringReference(uiViewSettingsId, uiViewSettingsIdLen, &uiViewSettingsIdRefHeader, &uiViewSettingsIdHs)))
+    if (FAILED(WindowsCreateStringReference(uiViewSettingsId, uiViewSettingsIdLen, &uiViewSettingsIdRefHeader, &uiViewSettingsIdHs)))
         return false;
 
     IUIViewSettingsInterop *uiViewSettingsInterop = nullptr;
     // __uuidof(IUIViewSettingsInterop);
     const GUID uiViewSettingsInteropRefId = {0x3694dbf9, 0x8f68, 0x44be,{0x8f, 0xf5, 0x19, 0x5c, 0x98, 0xed, 0xe8, 0xa6}};
 
-    HRESULT hr = baseComDll.roGetActivationFactory(uiViewSettingsIdHs, uiViewSettingsInteropRefId,
+    HRESULT hr = RoGetActivationFactory(uiViewSettingsIdHs, uiViewSettingsInteropRefId,
                                                    reinterpret_cast<void **>(&uiViewSettingsInterop));
     if (FAILED(hr))
         return false;
diff --git a/src/plugins/platforms/windows/qwindowsclipboard.cpp b/src/plugins/platforms/windows/qwindowsclipboard.cpp
index 01377a55e0..73111a13fb 100644
--- a/src/plugins/platforms/windows/qwindowsclipboard.cpp
+++ b/src/plugins/platforms/windows/qwindowsclipboard.cpp
@@ -191,12 +191,9 @@ void QWindowsClipboard::registerViewer()
         createDummyWindow(QStringLiteral("ClipboardView"), L"QtClipboardView",
                           qClipboardViewerWndProc, WS_OVERLAPPED);
 
-    // Try format listener API (Vista onwards) first.
-    if (QWindowsContext::user32dll.addClipboardFormatListener && QWindowsContext::user32dll.removeClipboardFormatListener) {
-        m_formatListenerRegistered = QWindowsContext::user32dll.addClipboardFormatListener(m_clipboardViewer);
-        if (!m_formatListenerRegistered)
-            qErrnoWarning("AddClipboardFormatListener() failed.");
-    }
+    m_formatListenerRegistered = AddClipboardFormatListener(m_clipboardViewer);
+    if (!m_formatListenerRegistered)
+        qErrnoWarning("AddClipboardFormatListener() failed.");
 
     if (!m_formatListenerRegistered)
         m_nextClipboardViewer = SetClipboardViewer(m_clipboardViewer);
@@ -210,7 +207,7 @@ void QWindowsClipboard::unregisterViewer()
 {
     if (m_clipboardViewer) {
         if (m_formatListenerRegistered) {
-            QWindowsContext::user32dll.removeClipboardFormatListener(m_clipboardViewer);
+            RemoveClipboardFormatListener(m_clipboardViewer);
             m_formatListenerRegistered = false;
         } else {
             ChangeClipboardChain(m_clipboardViewer, m_nextClipboardViewer);
diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 1c75f7f7d2..0538f42bec 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -77,11 +77,9 @@
 #include <QtCore/qlibraryinfo.h>
 #include <QtCore/qstringlist.h>
 #include <QtCore/qdebug.h>
-#include <QtCore/qoperatingsystemversion.h>
 #include <QtCore/qsysinfo.h>
 #include <QtCore/qscopedpointer.h>
 #include <QtCore/quuid.h>
-#include <QtCore/private/qsystemlibrary_p.h>
 #include <QtCore/private/qwinregistry_p.h>
 
 #include <QtGui/private/qwindowsguieventdispatcher_p.h>
@@ -92,6 +90,7 @@
 #include <comdef.h>
 #include <dbt.h>
 #include <wtsapi32.h>
+#include <shellscalingapi.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -153,17 +152,15 @@ static inline bool sessionManagerInteractionBlocked() { return false; }
 
 static inline int windowDpiAwareness(HWND hwnd)
 {
-    return QWindowsContext::user32dll.getWindowDpiAwarenessContext && QWindowsContext::user32dll.getAwarenessFromDpiAwarenessContext
-        ? QWindowsContext::user32dll.getAwarenessFromDpiAwarenessContext(QWindowsContext::user32dll.getWindowDpiAwarenessContext(hwnd))
-        : -1;
+    return static_cast<int>(GetAwarenessFromDpiAwarenessContext(GetWindowDpiAwarenessContext(hwnd)));
 }
 
 // Note: This only works within WM_NCCREATE
 static bool enableNonClientDpiScaling(HWND hwnd)
 {
     bool result = false;
-    if (QWindowsContext::user32dll.enableNonClientDpiScaling && windowDpiAwareness(hwnd) == 2) {
-        result = QWindowsContext::user32dll.enableNonClientDpiScaling(hwnd) != FALSE;
+    if (windowDpiAwareness(hwnd) == 2) {
+        result = EnableNonClientDpiScaling(hwnd) != FALSE;
         if (!result) {
             const DWORD errorCode = GetLastError();
             qErrnoWarning(int(errorCode), "EnableNonClientDpiScaling() failed for HWND %p (%lu)",
@@ -173,73 +170,6 @@ static bool enableNonClientDpiScaling(HWND hwnd)
     return result;
 }
 
-/*!
-    \class QWindowsUser32DLL
-    \brief Struct that contains dynamically resolved symbols of User32.dll.
-
-    The stub libraries shipped with the MinGW compiler miss some of the
-    functions. They need to be retrieved dynamically.
-
-    In addition, touch-related functions are available only from Windows onwards.
-    These need to resolved dynamically for Q_CC_MSVC as well.
-
-    \sa QWindowsShell32DLL
-
-    \internal
-*/
-
-void QWindowsUser32DLL::init()
-{
-    QSystemLibrary library(QStringLiteral("user32"));
-    setProcessDPIAware = (SetProcessDPIAware)library.resolve("SetProcessDPIAware");
-    setProcessDpiAwarenessContext = (SetProcessDpiAwarenessContext)library.resolve("SetProcessDpiAwarenessContext");
-
-    addClipboardFormatListener = (AddClipboardFormatListener)library.resolve("AddClipboardFormatListener");
-    removeClipboardFormatListener = (RemoveClipboardFormatListener)library.resolve("RemoveClipboardFormatListener");
-
-    getDisplayAutoRotationPreferences = (GetDisplayAutoRotationPreferences)library.resolve("GetDisplayAutoRotationPreferences");
-    setDisplayAutoRotationPreferences = (SetDisplayAutoRotationPreferences)library.resolve("SetDisplayAutoRotationPreferences");
-
-    enableMouseInPointer = (EnableMouseInPointer)library.resolve("EnableMouseInPointer");
-    getPointerType = (GetPointerType)library.resolve("GetPointerType");
-    getPointerInfo = (GetPointerInfo)library.resolve("GetPointerInfo");
-    getPointerDeviceRects = (GetPointerDeviceRects)library.resolve("GetPointerDeviceRects");
-    getPointerTouchInfo = (GetPointerTouchInfo)library.resolve("GetPointerTouchInfo");
-    getPointerFrameTouchInfo = (GetPointerFrameTouchInfo)library.resolve("GetPointerFrameTouchInfo");
-    getPointerFrameTouchInfoHistory = (GetPointerFrameTouchInfoHistory)library.resolve("GetPointerFrameTouchInfoHistory");
-    getPointerPenInfo = (GetPointerPenInfo)library.resolve("GetPointerPenInfo");
-    getPointerPenInfoHistory = (GetPointerPenInfoHistory)library.resolve("GetPointerPenInfoHistory");
-    skipPointerFrameMessages = (SkipPointerFrameMessages)library.resolve("SkipPointerFrameMessages");
-
-    if (QOperatingSystemVersion::current()
-        >= QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0, 14393)) {
-        adjustWindowRectExForDpi = (AdjustWindowRectExForDpi)library.resolve("AdjustWindowRectExForDpi");
-        enableNonClientDpiScaling = (EnableNonClientDpiScaling)library.resolve("EnableNonClientDpiScaling");
-        getWindowDpiAwarenessContext = (GetWindowDpiAwarenessContext)library.resolve("GetWindowDpiAwarenessContext");
-        getAwarenessFromDpiAwarenessContext = (GetAwarenessFromDpiAwarenessContext)library.resolve("GetAwarenessFromDpiAwarenessContext");
-        systemParametersInfoForDpi = (SystemParametersInfoForDpi)library.resolve("SystemParametersInfoForDpi");
-        getDpiForWindow = (GetDpiForWindow)library.resolve("GetDpiForWindow");
-    }
-}
-
-bool QWindowsUser32DLL::supportsPointerApi()
-{
-    return enableMouseInPointer && getPointerType && getPointerInfo && getPointerDeviceRects
-            && getPointerTouchInfo && getPointerFrameTouchInfo && getPointerFrameTouchInfoHistory
-            && getPointerPenInfo && getPointerPenInfoHistory && skipPointerFrameMessages;
-}
-
-void QWindowsShcoreDLL::init()
-{
-    QSystemLibrary library(QStringLiteral("SHCore"));
-    getProcessDpiAwareness = (GetProcessDpiAwareness)library.resolve("GetProcessDpiAwareness");
-    setProcessDpiAwareness = (SetProcessDpiAwareness)library.resolve("SetProcessDpiAwareness");
-    getDpiForMonitor = (GetDpiForMonitor)library.resolve("GetDpiForMonitor");
-}
-
-QWindowsUser32DLL QWindowsContext::user32dll;
-QWindowsShcoreDLL QWindowsContext::shcoredll;
-
 QWindowsContext *QWindowsContext::m_instance = nullptr;
 
 /*!
@@ -285,9 +215,6 @@ bool QWindowsContextPrivate::m_v2DpiAware = false;
 QWindowsContextPrivate::QWindowsContextPrivate()
     : m_oleInitializeResult(OleInitialize(nullptr))
 {
-    QWindowsContext::user32dll.init();
-    QWindowsContext::shcoredll.init();
-
     if (m_pointerHandler.touchDevice() || m_mouseHandler.touchDevice())
         m_systemInfo |= QWindowsContext::SI_SupportsTouch;
     m_displayContext = GetDC(nullptr);
@@ -402,9 +329,6 @@ bool QWindowsContext::initPointer(unsigned integrationOptions)
     if (integrationOptions & QWindowsIntegration::DontUseWMPointer)
         return false;
 
-    if (!QWindowsContext::user32dll.supportsPointerApi())
-        return false;
-
     d->m_systemInfo |= QWindowsContext::SI_SupportsPointer;
     return true;
 }
@@ -474,10 +398,9 @@ void QWindowsContext::setDetectAltGrModifier(bool a)
 
 int QWindowsContext::processDpiAwareness()
 {
-    int result;
-    if (QWindowsContext::shcoredll.getProcessDpiAwareness
-        && SUCCEEDED(QWindowsContext::shcoredll.getProcessDpiAwareness(nullptr, &result))) {
-        return result;
+    PROCESS_DPI_AWARENESS result;
+    if (SUCCEEDED(GetProcessDpiAwareness(nullptr, &result))) {
+        return static_cast<int>(result);
     }
     return -1;
 }
@@ -485,27 +408,20 @@ int QWindowsContext::processDpiAwareness()
 void QWindowsContext::setProcessDpiAwareness(QtWindows::ProcessDpiAwareness dpiAwareness)
 {
     qCDebug(lcQpaWindows) << __FUNCTION__ << dpiAwareness;
-    if (QWindowsContext::shcoredll.isValid()) {
-        const HRESULT hr = QWindowsContext::shcoredll.setProcessDpiAwareness(dpiAwareness);
-        // E_ACCESSDENIED means set externally (MSVC manifest or external app loading Qt plugin).
-        // Silence warning in that case unless debug is enabled.
-        if (FAILED(hr) && (hr != E_ACCESSDENIED || lcQpaWindows().isDebugEnabled())) {
-            qWarning().noquote().nospace() << "SetProcessDpiAwareness("
-                << dpiAwareness << ") failed: " << QWindowsContext::comErrorString(hr)
-                << ", using " << QWindowsContext::processDpiAwareness();
-        }
-    } else {
-        if (dpiAwareness != QtWindows::ProcessDpiUnaware && QWindowsContext::user32dll.setProcessDPIAware) {
-            if (!QWindowsContext::user32dll.setProcessDPIAware())
-                qErrnoWarning("SetProcessDPIAware() failed");
-        }
+    const HRESULT hr = SetProcessDpiAwareness(static_cast<PROCESS_DPI_AWARENESS>(dpiAwareness));
+    // E_ACCESSDENIED means set externally (MSVC manifest or external app loading Qt plugin).
+    // Silence warning in that case unless debug is enabled.
+    if (FAILED(hr) && (hr != E_ACCESSDENIED || lcQpaWindows().isDebugEnabled())) {
+        qWarning().noquote().nospace() << "SetProcessDpiAwareness("
+            << dpiAwareness << ") failed: " << QWindowsContext::comErrorString(hr)
+            << ", using " << QWindowsContext::processDpiAwareness();
     }
 }
 
 void QWindowsContext::setProcessDpiV2Awareness()
 {
     qCDebug(lcQpaWindows) << __FUNCTION__;
-    const BOOL ok = QWindowsContext::user32dll.setProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
+    const BOOL ok = SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
     if (ok) {
         QWindowsContextPrivate::m_v2DpiAware = true;
     } else {
@@ -1046,8 +962,8 @@ void QWindowsContext::forceNcCalcSize(HWND hwnd)
 bool QWindowsContext::systemParametersInfo(unsigned action, unsigned param, void *out,
                                            unsigned dpi)
 {
-    const BOOL result = QWindowsContext::user32dll.systemParametersInfoForDpi != nullptr && dpi != 0
-        ? QWindowsContext::user32dll.systemParametersInfoForDpi(action, param, out, 0, dpi)
+    const BOOL result = dpi != 0
+        ? SystemParametersInfoForDpi(action, param, out, 0, dpi)
         : SystemParametersInfo(action, param, out, 0);
     return result == TRUE;
 }
@@ -1094,8 +1010,7 @@ bool QWindowsContext::shouldHaveNonClientDpiScaling(const QWindow *window)
     if (QWindowsContextPrivate::m_v2DpiAware)
         return true;
 
-    return QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows10
-        && window->isTopLevel()
+    return window->isTopLevel()
         && !window->property(QWindowsWindow::embeddedNativeParentHandleProperty).isValid()
 #if QT_CONFIG(opengl) // /QTBUG-62901, EnableNonClientDpiScaling has problems with GL
         && (window->surfaceType() != QSurface::OpenGLSurface
diff --git a/src/plugins/platforms/windows/qwindowscontext.h b/src/plugins/platforms/windows/qwindowscontext.h
index 04328a0369..d1d5139fb3 100644
--- a/src/plugins/platforms/windows/qwindowscontext.h
+++ b/src/plugins/platforms/windows/qwindowscontext.h
@@ -82,85 +82,6 @@ class QPoint;
 class QKeyEvent;
 class QPointingDevice;
 
-struct QWindowsUser32DLL
-{
-    inline void init();
-    inline bool supportsPointerApi();
-
-    typedef BOOL (WINAPI *EnableMouseInPointer)(BOOL);
-    typedef BOOL (WINAPI *GetPointerType)(UINT32, PVOID);
-    typedef BOOL (WINAPI *GetPointerInfo)(UINT32, PVOID);
-    typedef BOOL (WINAPI *GetPointerDeviceRects)(HANDLE, RECT *, RECT *);
-    typedef BOOL (WINAPI *GetPointerTouchInfo)(UINT32, PVOID);
-    typedef BOOL (WINAPI *GetPointerFrameTouchInfo)(UINT32, UINT32 *, PVOID);
-    typedef BOOL (WINAPI *GetPointerFrameTouchInfoHistory)(UINT32, UINT32 *, UINT32 *, PVOID);
-    typedef BOOL (WINAPI *GetPointerPenInfo)(UINT32, PVOID);
-    typedef BOOL (WINAPI *GetPointerPenInfoHistory)(UINT32, UINT32 *, PVOID);
-    typedef BOOL (WINAPI *SkipPointerFrameMessages)(UINT32);
-    typedef BOOL (WINAPI *SetProcessDPIAware)();
-    typedef BOOL (WINAPI *SetProcessDpiAwarenessContext)(HANDLE);
-    typedef BOOL (WINAPI *AddClipboardFormatListener)(HWND);
-    typedef BOOL (WINAPI *RemoveClipboardFormatListener)(HWND);
-    typedef BOOL (WINAPI *GetDisplayAutoRotationPreferences)(DWORD *);
-    typedef BOOL (WINAPI *SetDisplayAutoRotationPreferences)(DWORD);
-    typedef BOOL (WINAPI *AdjustWindowRectExForDpi)(LPRECT,DWORD,BOOL,DWORD,UINT);
-    typedef BOOL (WINAPI *EnableNonClientDpiScaling)(HWND);
-    typedef int  (WINAPI *GetWindowDpiAwarenessContext)(HWND);
-    typedef int  (WINAPI *GetAwarenessFromDpiAwarenessContext)(int);
-    typedef BOOL (WINAPI *SystemParametersInfoForDpi)(UINT, UINT, PVOID, UINT, UINT);
-    typedef int  (WINAPI *GetDpiForWindow)(HWND);
-
-    // Windows pointer functions (Windows 8 or later).
-    EnableMouseInPointer enableMouseInPointer = nullptr;
-    GetPointerType getPointerType = nullptr;
-    GetPointerInfo getPointerInfo = nullptr;
-    GetPointerDeviceRects getPointerDeviceRects = nullptr;
-    GetPointerTouchInfo getPointerTouchInfo = nullptr;
-    GetPointerFrameTouchInfo getPointerFrameTouchInfo = nullptr;
-    GetPointerFrameTouchInfoHistory getPointerFrameTouchInfoHistory = nullptr;
-    GetPointerPenInfo getPointerPenInfo = nullptr;
-    GetPointerPenInfoHistory getPointerPenInfoHistory = nullptr;
-    SkipPointerFrameMessages skipPointerFrameMessages = nullptr;
-
-    // Windows Vista onwards
-    SetProcessDPIAware setProcessDPIAware = nullptr;
-
-    // Windows 10 version 1607 onwards
-    GetDpiForWindow getDpiForWindow = nullptr;
-
-    // Windows 10 version 1703 onwards
-    SetProcessDpiAwarenessContext setProcessDpiAwarenessContext = nullptr;
-
-    // Clipboard listeners are present on Windows Vista onwards
-    // but missing in MinGW 4.9 stub libs. Can be removed in MinGW 5.
-    AddClipboardFormatListener addClipboardFormatListener = nullptr;
-    RemoveClipboardFormatListener removeClipboardFormatListener = nullptr;
-
-    // Rotation API
-    GetDisplayAutoRotationPreferences getDisplayAutoRotationPreferences = nullptr;
-    SetDisplayAutoRotationPreferences setDisplayAutoRotationPreferences = nullptr;
-
-    AdjustWindowRectExForDpi adjustWindowRectExForDpi = nullptr;
-    EnableNonClientDpiScaling enableNonClientDpiScaling = nullptr;
-    GetWindowDpiAwarenessContext getWindowDpiAwarenessContext = nullptr;
-    GetAwarenessFromDpiAwarenessContext getAwarenessFromDpiAwarenessContext = nullptr;
-    SystemParametersInfoForDpi systemParametersInfoForDpi = nullptr;
-};
-
-// Shell scaling library (Windows 8.1 onwards)
-struct QWindowsShcoreDLL {
-    void init();
-    inline bool isValid() const { return getProcessDpiAwareness && setProcessDpiAwareness && getDpiForMonitor; }
-
-    typedef HRESULT (WINAPI *GetProcessDpiAwareness)(HANDLE,int *);
-    typedef HRESULT (WINAPI *SetProcessDpiAwareness)(int);
-    typedef HRESULT (WINAPI *GetDpiForMonitor)(HMONITOR,int,UINT *,UINT *);
-
-    GetProcessDpiAwareness getProcessDpiAwareness = nullptr;
-    SetProcessDpiAwareness setProcessDpiAwareness = nullptr;
-    GetDpiForMonitor getDpiForMonitor = nullptr;
-};
-
 class QWindowsContext
 {
     Q_DISABLE_COPY_MOVE(QWindowsContext)
@@ -253,9 +174,6 @@ public:
     QWindowsScreenManager &screenManager();
     QWindowsTabletSupport *tabletSupport() const;
 
-    static QWindowsUser32DLL user32dll;
-    static QWindowsShcoreDLL shcoredll;
-
     static QByteArray comErrorString(HRESULT hr);
     bool asyncExpose() const;
     void setAsyncExpose(bool value);
diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index 5524129418..e8399bd3d2 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -70,7 +70,6 @@
 #include <QtCore/qmutex.h>
 #include <QtCore/quuid.h>
 #include <QtCore/qtemporaryfile.h>
-#include <QtCore/private/qsystemlibrary_p.h>
 
 #include <algorithm>
 #include <vector>
@@ -1707,9 +1706,6 @@ public slots:
     void close() override {}
 
 private:
-    typedef BOOL (APIENTRY *PtrGetOpenFileNameW)(LPOPENFILENAMEW);
-    typedef BOOL (APIENTRY *PtrGetSaveFileNameW)(LPOPENFILENAMEW);
-
     explicit QWindowsXpNativeFileDialog(const OptionsPtr &options, const QWindowsFileDialogSharedData &data);
     void populateOpenFileName(OPENFILENAME *ofn, HWND owner) const;
     QList<QUrl> execExistingDir(HWND owner);
@@ -1719,27 +1715,11 @@ private:
     QString m_title;
     QPlatformDialogHelper::DialogCode m_result;
     QWindowsFileDialogSharedData m_data;
-
-    static PtrGetOpenFileNameW m_getOpenFileNameW;
-    static PtrGetSaveFileNameW m_getSaveFileNameW;
 };
 
-QWindowsXpNativeFileDialog::PtrGetOpenFileNameW QWindowsXpNativeFileDialog::m_getOpenFileNameW = nullptr;
-QWindowsXpNativeFileDialog::PtrGetSaveFileNameW QWindowsXpNativeFileDialog::m_getSaveFileNameW = nullptr;
-
 QWindowsXpNativeFileDialog *QWindowsXpNativeFileDialog::create(const OptionsPtr &options, const QWindowsFileDialogSharedData &data)
 {
-    // GetOpenFileNameW() GetSaveFileName() are resolved
-    // dynamically as not to create a dependency on Comdlg32, which
-    // is used on XP only.
-    if (!m_getOpenFileNameW) {
-        QSystemLibrary library(QStringLiteral("Comdlg32"));
-        m_getOpenFileNameW = (PtrGetOpenFileNameW)(library.resolve("GetOpenFileNameW"));
-        m_getSaveFileNameW = (PtrGetSaveFileNameW)(library.resolve("GetSaveFileNameW"));
-    }
-    if (m_getOpenFileNameW && m_getSaveFileNameW)
-        return new QWindowsXpNativeFileDialog(options, data);
-    return nullptr;
+    return new QWindowsXpNativeFileDialog(options, data);
 }
 
 QWindowsXpNativeFileDialog::QWindowsXpNativeFileDialog(const OptionsPtr &options,
@@ -1903,7 +1883,7 @@ QList<QUrl> QWindowsXpNativeFileDialog::execFileNames(HWND owner, int *selectedF
     populateOpenFileName(&ofn, owner);
     QList<QUrl> result;
     const bool isSave = m_options->acceptMode() == QFileDialogOptions::AcceptSave;
-    if (isSave ? m_getSaveFileNameW(&ofn) : m_getOpenFileNameW(&ofn)) {
+    if (isSave ? GetSaveFileNameW(&ofn) : GetOpenFileNameW(&ofn)) {
         *selectedFilterIndex = ofn.nFilterIndex - 1;
         const QString dir = QDir::cleanPath(QString::fromWCharArray(ofn.lpstrFile));
         result.push_back(QUrl::fromLocalFile(dir));
@@ -2045,8 +2025,6 @@ QWindowsNativeColorDialog::QWindowsNativeColorDialog(const SharedPointerColor &c
 
 void QWindowsNativeColorDialog::doExec(HWND owner)
 {
-    typedef BOOL (WINAPI *ChooseColorWType)(LPCHOOSECOLORW);
-
     CHOOSECOLOR chooseColor;
     ZeroMemory(&chooseColor, sizeof(chooseColor));
     chooseColor.lStructSize = sizeof(chooseColor);
@@ -2059,18 +2037,9 @@ void QWindowsNativeColorDialog::doExec(HWND owner)
         m_customColors[c] = qColorToCOLORREF(QColor(qCustomColors[c]));
     chooseColor.rgbResult = qColorToCOLORREF(*m_color);
     chooseColor.Flags = CC_FULLOPEN | CC_RGBINIT;
-    static ChooseColorWType chooseColorW = 0;
-    if (!chooseColorW) {
-        QSystemLibrary library(QStringLiteral("Comdlg32"));
-        chooseColorW = (ChooseColorWType)library.resolve("ChooseColorW");
-    }
-    if (chooseColorW) {
-        m_code = chooseColorW(&chooseColor) ?
-            QPlatformDialogHelper::Accepted : QPlatformDialogHelper::Rejected;
-        QWindowsDialogs::eatMouseMove();
-    } else {
-        m_code = QPlatformDialogHelper::Rejected;
-    }
+    m_code = ChooseColorW(&chooseColor) ?
+        QPlatformDialogHelper::Accepted : QPlatformDialogHelper::Rejected;
+    QWindowsDialogs::eatMouseMove();
     if (m_code == QPlatformDialogHelper::Accepted) {
         *m_color = COLORREFToQColor(chooseColor.rgbResult);
         for (int c= 0; c < customColorCount; ++c)
diff --git a/src/plugins/platforms/windows/qwindowsinputcontext.cpp b/src/plugins/platforms/windows/qwindowsinputcontext.cpp
index 03be0b9451..4cda4e1efe 100644
--- a/src/plugins/platforms/windows/qwindowsinputcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowsinputcontext.cpp
@@ -47,7 +47,6 @@
 #include <QtCore/qobject.h>
 #include <QtCore/qrect.h>
 #include <QtCore/qtextboundaryfinder.h>
-#include <QtCore/qoperatingsystemversion.h>
 
 #include <QtGui/qevent.h>
 #include <QtGui/qtextformat.h>
@@ -285,9 +284,7 @@ void QWindowsInputContext::showInputPanel()
         // Only trigger the native OSK if the Qt OSK is not in use.
         static bool imModuleEmpty = qEnvironmentVariableIsEmpty("QT_IM_MODULE");
         bool nativeVKDisabled = QCoreApplication::testAttribute(Qt::AA_DisableNativeVirtualKeyboard);
-        if ((imModuleEmpty && !nativeVKDisabled)
-                && QOperatingSystemVersion::current()
-                    >= QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0, 16299)) {
+        if (imModuleEmpty && !nativeVKDisabled) {
             ShowCaret(platformWindow->handle());
         } else {
             HideCaret(platformWindow->handle());
diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index 822c11d0f2..397b988e61 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -122,14 +122,6 @@ QT_BEGIN_NAMESPACE
         MinGW-w64 provides more complete headers (compared to stock MinGW from mingw.org),
         including a considerable part of the Windows SDK.
     \endlist
-
-    When using a function from the WinAPI, the minimum supported Windows version
-    and Windows Embedded support should be checked. If the function is not supported
-    on Windows XP or is not present in the MinGW-headers, it should be dynamically
-    resolved. For this purpose, QWindowsContext has static structs like
-    QWindowsUser32DLL and QWindowsShell32DLL. All function pointers should go to
-    these structs to avoid lookups in several places.
-
 */
 
 struct QWindowsIntegrationPrivate
@@ -245,10 +237,8 @@ void QWindowsIntegrationPrivate::parseOptions(QWindowsIntegration *q, const QStr
     initOpenGlBlacklistResources();
 
     static bool dpiAwarenessSet = false;
-    static bool hasDpiAwarenessContext = QWindowsContext::user32dll.setProcessDpiAwarenessContext != nullptr;
     // Default to per-monitor-v2 awareness (if available)
-    QtWindows::ProcessDpiAwareness dpiAwareness = hasDpiAwarenessContext ?
-        QtWindows::ProcessPerMonitorV2DpiAware : QtWindows::ProcessPerMonitorDpiAware;
+    QtWindows::ProcessDpiAwareness dpiAwareness = QtWindows::ProcessPerMonitorV2DpiAware;
 
     int tabletAbsoluteRange = -1;
     DarkModeHandling darkModeHandling;
@@ -267,7 +257,7 @@ void QWindowsIntegrationPrivate::parseOptions(QWindowsIntegration *q, const QStr
         if (!QCoreApplication::testAttribute(Qt::AA_PluginApplication)) {
 
             // DpiAwareV2 requires using new API
-            if (dpiAwareness == QtWindows::ProcessPerMonitorV2DpiAware && hasDpiAwarenessContext) {
+            if (dpiAwareness == QtWindows::ProcessPerMonitorV2DpiAware) {
                 m_context.setProcessDpiV2Awareness();
                 qCDebug(lcQpaWindows)
                     << __FUNCTION__ << "DpiAwareness: DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2";
diff --git a/src/plugins/platforms/windows/qwindowsopengltester.cpp b/src/plugins/platforms/windows/qwindowsopengltester.cpp
index 0b1af47a65..59bdb38fad 100644
--- a/src/plugins/platforms/windows/qwindowsopengltester.cpp
+++ b/src/plugins/platforms/windows/qwindowsopengltester.cpp
@@ -55,7 +55,6 @@
 #endif
 
 #include <QtCore/qt_windows.h>
-#include <private/qsystemlibrary_p.h>
 #include <d3d9.h>
 
 QT_BEGIN_NAMESPACE
@@ -94,19 +93,12 @@ public:
     bool retrieveAdapterIdentifier(UINT n, D3DADAPTER_IDENTIFIER9 *adapterIdentifier) const;
 
 private:
-    QSystemLibrary m_d3d9lib;
     IDirect3D9 *m_direct3D9 = nullptr;
 };
 
-QDirect3D9Handle::QDirect3D9Handle() :
-    m_d3d9lib(QStringLiteral("d3d9"))
+QDirect3D9Handle::QDirect3D9Handle()
 {
-    using PtrDirect3DCreate9 = IDirect3D9 *(WINAPI *)(UINT);
-
-    if (m_d3d9lib.load()) {
-        if (auto direct3DCreate9 = (PtrDirect3DCreate9)m_d3d9lib.resolve("Direct3DCreate9"))
-            m_direct3D9 = direct3DCreate9(D3D_SDK_VERSION);
-    }
+    m_direct3D9 = Direct3DCreate9(D3D_SDK_VERSION);
 }
 
 QDirect3D9Handle::~QDirect3D9Handle()
diff --git a/src/plugins/platforms/windows/qwindowspointerhandler.cpp b/src/plugins/platforms/windows/qwindowspointerhandler.cpp
index 7f8d0e54de..dc74e28a12 100644
--- a/src/plugins/platforms/windows/qwindowspointerhandler.cpp
+++ b/src/plugins/platforms/windows/qwindowspointerhandler.cpp
@@ -59,7 +59,6 @@
 #include <QtGui/private/qguiapplication_p.h>
 #include <QtCore/qvarlengtharray.h>
 #include <QtCore/qloggingcategory.h>
-#include <QtCore/qoperatingsystemversion.h>
 #include <QtCore/qqueue.h>
 
 #include <algorithm>
@@ -87,7 +86,7 @@ bool QWindowsPointerHandler::translatePointerEvent(QWindow *window, HWND hwnd, Q
     *result = 0;
     const quint32 pointerId = GET_POINTERID_WPARAM(msg.wParam);
 
-    if (!QWindowsContext::user32dll.getPointerType(pointerId, &m_pointerType)) {
+    if (!GetPointerType(pointerId, &m_pointerType)) {
         qWarning() << "GetPointerType() failed:" << qt_error_string();
         return false;
     }
@@ -101,12 +100,12 @@ bool QWindowsPointerHandler::translatePointerEvent(QWindow *window, HWND hwnd, Q
     }
     case QT_PT_TOUCH: {
         quint32 pointerCount = 0;
-        if (!QWindowsContext::user32dll.getPointerFrameTouchInfo(pointerId, &pointerCount, nullptr)) {
+        if (!GetPointerFrameTouchInfo(pointerId, &pointerCount, nullptr)) {
             qWarning() << "GetPointerFrameTouchInfo() failed:" << qt_error_string();
             return false;
         }
         QVarLengthArray<POINTER_TOUCH_INFO, 10> touchInfo(pointerCount);
-        if (!QWindowsContext::user32dll.getPointerFrameTouchInfo(pointerId, &pointerCount, touchInfo.data())) {
+        if (!GetPointerFrameTouchInfo(pointerId, &pointerCount, touchInfo.data())) {
             qWarning() << "GetPointerFrameTouchInfo() failed:" << qt_error_string();
             return false;
         }
@@ -119,10 +118,10 @@ bool QWindowsPointerHandler::translatePointerEvent(QWindow *window, HWND hwnd, Q
         // dispatch any skipped frames if event compression is disabled by the app
         if (historyCount > 1 && !QCoreApplication::testAttribute(Qt::AA_CompressHighFrequencyEvents)) {
             touchInfo.resize(pointerCount * historyCount);
-            if (!QWindowsContext::user32dll.getPointerFrameTouchInfoHistory(pointerId,
-                                                                            &historyCount,
-                                                                            &pointerCount,
-                                                                            touchInfo.data())) {
+            if (!GetPointerFrameTouchInfoHistory(pointerId,
+                                                 &historyCount,
+                                                 &pointerCount,
+                                                 touchInfo.data())) {
                 qWarning() << "GetPointerFrameTouchInfoHistory() failed:" << qt_error_string();
                 return false;
             }
@@ -140,7 +139,7 @@ bool QWindowsPointerHandler::translatePointerEvent(QWindow *window, HWND hwnd, Q
     }
     case QT_PT_PEN: {
         POINTER_PEN_INFO penInfo;
-        if (!QWindowsContext::user32dll.getPointerPenInfo(pointerId, &penInfo)) {
+        if (!GetPointerPenInfo(pointerId, &penInfo)) {
             qWarning() << "GetPointerPenInfo() failed:" << qt_error_string();
             return false;
         }
@@ -152,9 +151,7 @@ bool QWindowsPointerHandler::translatePointerEvent(QWindow *window, HWND hwnd, Q
                 || !QCoreApplication::testAttribute(Qt::AA_CompressTabletEvents))) {
             QVarLengthArray<POINTER_PEN_INFO, 10> penInfoHistory(historyCount);
 
-            if (!QWindowsContext::user32dll.getPointerPenInfoHistory(pointerId,
-                                                                     &historyCount,
-                                                                     penInfoHistory.data())) {
+            if (!GetPointerPenInfoHistory(pointerId, &historyCount, penInfoHistory.data())) {
                 qWarning() << "GetPointerPenInfoHistory() failed:" << qt_error_string();
                 return false;
             }
@@ -558,7 +555,7 @@ bool QWindowsPointerHandler::translateTouchEvent(QWindow *window, HWND hwnd,
         inputIds.insert(touchPoint.id);
 
         // Avoid getting repeated messages for this frame if there are multiple pointerIds
-        QWindowsContext::user32dll.skipPointerFrameMessages(touchInfo[i].pointerInfo.pointerId);
+        SkipPointerFrameMessages(touchInfo[i].pointerInfo.pointerId);
     }
 
     // Some devices send touches for each finger in a different message/frame, instead of consolidating
@@ -604,7 +601,7 @@ bool QWindowsPointerHandler::translatePenEvent(QWindow *window, HWND hwnd, QtWin
     auto *penInfo = static_cast<POINTER_PEN_INFO *>(vPenInfo);
 
     RECT pRect, dRect;
-    if (!QWindowsContext::user32dll.getPointerDeviceRects(penInfo->pointerInfo.sourceDevice, &pRect, &dRect))
+    if (!GetPointerDeviceRects(penInfo->pointerInfo.sourceDevice, &pRect, &dRect))
         return false;
 
     const auto systemId = (qint64)penInfo->pointerInfo.sourceDevice;
diff --git a/src/plugins/platforms/windows/qwindowsscreen.cpp b/src/plugins/platforms/windows/qwindowsscreen.cpp
index 2544dd6200..4474905744 100644
--- a/src/plugins/platforms/windows/qwindowsscreen.cpp
+++ b/src/plugins/platforms/windows/qwindowsscreen.cpp
@@ -56,6 +56,8 @@
 
 #include <QtCore/qdebug.h>
 
+#include <shellscalingapi.h>
+
 QT_BEGIN_NAMESPACE
 
 static inline QDpi deviceDPI(HDC hdc)
@@ -65,12 +67,10 @@ static inline QDpi deviceDPI(HDC hdc)
 
 static inline QDpi monitorDPI(HMONITOR hMonitor)
 {
-    if (QWindowsContext::shcoredll.isValid()) {
-        UINT dpiX;
-        UINT dpiY;
-        if (SUCCEEDED(QWindowsContext::shcoredll.getDpiForMonitor(hMonitor, 0, &dpiX, &dpiY)))
-            return QDpi(dpiX, dpiY);
-    }
+    UINT dpiX;
+    UINT dpiY;
+    if (SUCCEEDED(GetDpiForMonitor(hMonitor, MDT_EFFECTIVE_DPI, &dpiX, &dpiY)))
+        return QDpi(dpiX, dpiY);
     return {0, 0};
 }
 
@@ -429,62 +429,50 @@ QRect QWindowsScreen::virtualGeometry(const QPlatformScreen *screen) // cf QScre
     return result;
 }
 
-enum OrientationPreference : DWORD // matching Win32 API ORIENTATION_PREFERENCE
-{
-    orientationPreferenceNone = 0,
-    orientationPreferenceLandscape = 0x1,
-    orientationPreferencePortrait = 0x2,
-    orientationPreferenceLandscapeFlipped = 0x4,
-    orientationPreferencePortraitFlipped = 0x8
-};
-
 bool QWindowsScreen::setOrientationPreference(Qt::ScreenOrientation o)
 {
     bool result = false;
-    if (QWindowsContext::user32dll.setDisplayAutoRotationPreferences) {
-        DWORD orientationPreference = 0;
-        switch (o) {
-        case Qt::PrimaryOrientation:
-            orientationPreference = orientationPreferenceNone;
-            break;
-        case Qt::PortraitOrientation:
-            orientationPreference = orientationPreferencePortrait;
-            break;
-        case Qt::LandscapeOrientation:
-            orientationPreference = orientationPreferenceLandscape;
-            break;
-        case Qt::InvertedPortraitOrientation:
-            orientationPreference = orientationPreferencePortraitFlipped;
-            break;
-        case Qt::InvertedLandscapeOrientation:
-            orientationPreference = orientationPreferenceLandscapeFlipped;
-            break;
-        }
-        result = QWindowsContext::user32dll.setDisplayAutoRotationPreferences(orientationPreference);
+    ORIENTATION_PREFERENCE orientationPreference = ORIENTATION_PREFERENCE_NONE;
+    switch (o) {
+    case Qt::PrimaryOrientation:
+        break;
+    case Qt::PortraitOrientation:
+        orientationPreference = ORIENTATION_PREFERENCE_PORTRAIT;
+        break;
+    case Qt::LandscapeOrientation:
+        orientationPreference = ORIENTATION_PREFERENCE_LANDSCAPE;
+        break;
+    case Qt::InvertedPortraitOrientation:
+        orientationPreference = ORIENTATION_PREFERENCE_PORTRAIT_FLIPPED;
+        break;
+    case Qt::InvertedLandscapeOrientation:
+        orientationPreference = ORIENTATION_PREFERENCE_LANDSCAPE_FLIPPED;
+        break;
     }
+    result = SetDisplayAutoRotationPreferences(orientationPreference);
     return result;
 }
 
 Qt::ScreenOrientation QWindowsScreen::orientationPreference()
 {
     Qt::ScreenOrientation result = Qt::PrimaryOrientation;
-    if (QWindowsContext::user32dll.getDisplayAutoRotationPreferences) {
-        DWORD orientationPreference = 0;
-        if (QWindowsContext::user32dll.getDisplayAutoRotationPreferences(&orientationPreference)) {
-            switch (orientationPreference) {
-            case orientationPreferenceLandscape:
-                result = Qt::LandscapeOrientation;
-                break;
-            case orientationPreferencePortrait:
-                result = Qt::PortraitOrientation;
-                break;
-            case orientationPreferenceLandscapeFlipped:
-                result = Qt::InvertedLandscapeOrientation;
-                break;
-            case orientationPreferencePortraitFlipped:
-                result = Qt::InvertedPortraitOrientation;
-                break;
-            }
+    ORIENTATION_PREFERENCE orientationPreference = ORIENTATION_PREFERENCE_NONE;
+    if (GetDisplayAutoRotationPreferences(&orientationPreference)) {
+        switch (orientationPreference) {
+        case ORIENTATION_PREFERENCE_NONE:
+            break;
+        case ORIENTATION_PREFERENCE_LANDSCAPE:
+            result = Qt::LandscapeOrientation;
+            break;
+        case ORIENTATION_PREFERENCE_PORTRAIT:
+            result = Qt::PortraitOrientation;
+            break;
+        case ORIENTATION_PREFERENCE_LANDSCAPE_FLIPPED:
+            result = Qt::InvertedLandscapeOrientation;
+            break;
+        case ORIENTATION_PREFERENCE_PORTRAIT_FLIPPED:
+            result = Qt::InvertedPortraitOrientation;
+            break;
         }
     }
     return result;
diff --git a/src/plugins/platforms/windows/qwindowstheme.cpp b/src/plugins/platforms/windows/qwindowstheme.cpp
index 85b6c30086..9ee6bbd79a 100644
--- a/src/plugins/platforms/windows/qwindowstheme.cpp
+++ b/src/plugins/platforms/windows/qwindowstheme.cpp
@@ -63,7 +63,6 @@
 #include <QtCore/qcoreapplication.h>
 #include <QtCore/qdebug.h>
 #include <QtCore/qtextstream.h>
-#include <QtCore/qoperatingsystemversion.h>
 #include <QtCore/qsysinfo.h>
 #include <QtCore/qcache.h>
 #include <QtCore/qthread.h>
@@ -1053,9 +1052,7 @@ bool QWindowsTheme::useNativeMenus()
 
 bool QWindowsTheme::queryDarkMode()
 {
-    if (QOperatingSystemVersion::current()
-        < QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0, 17763)
-        || queryHighContrast()) {
+    if (queryHighContrast()) {
         return false;
     }
     const auto setting = QWinRegistryKey(HKEY_CURRENT_USER, LR"(Software\Microsoft\Windows\CurrentVersion\Themes\Personalize)")
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index c4a85ab21e..53fbc167da 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -65,7 +65,6 @@
 #include <QtGui/qwindow.h>
 #include <QtGui/qregion.h>
 #include <QtGui/qopenglcontext.h>
-#include <private/qsystemlibrary_p.h>
 #include <private/qwindow_p.h> // QWINDOWSIZE_MAX
 #include <private/qguiapplication_p.h>
 #include <private/qhighdpiscaling_p.h>
@@ -73,7 +72,6 @@
 
 #include <QtCore/qdebug.h>
 #include <QtCore/qlibraryinfo.h>
-#include <QtCore/qoperatingsystemversion.h>
 
 #include <dwmapi.h>
 
@@ -81,6 +79,8 @@
 #include "qwindowsvulkaninstance.h"
 #endif
 
+#include <shellscalingapi.h>
+
 QT_BEGIN_NAMESPACE
 
 using QWindowCreationContextPtr = QSharedPointer<QWindowCreationContext>;
@@ -436,18 +436,14 @@ static inline void updateGLWindowSettings(const QWindow *w, HWND hwnd, Qt::Windo
 
 static QMargins invisibleMargins(QPoint screenPoint)
 {
-    if (QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows10) {
-        POINT pt = {screenPoint.x(), screenPoint.y()};
-        if (HMONITOR hMonitor = MonitorFromPoint(pt, MONITOR_DEFAULTTONULL)) {
-            if (QWindowsContext::shcoredll.isValid()) {
-                UINT dpiX;
-                UINT dpiY;
-                if (SUCCEEDED(QWindowsContext::shcoredll.getDpiForMonitor(hMonitor, 0, &dpiX, &dpiY))) {
-                    const qreal sc = (dpiX - 96) / 96.0;
-                    const int gap = 7 + qRound(5*sc) - int(sc);
-                    return QMargins(gap, 0, gap, gap);
-                }
-            }
+    POINT pt = {screenPoint.x(), screenPoint.y()};
+    if (HMONITOR hMonitor = MonitorFromPoint(pt, MONITOR_DEFAULTTONULL)) {
+        UINT dpiX;
+        UINT dpiY;
+        if (SUCCEEDED(GetDpiForMonitor(hMonitor, MDT_EFFECTIVE_DPI, &dpiX, &dpiY))) {
+            const qreal sc = (dpiX - 96) / 96.0;
+            const int gap = 7 + qRound(5*sc) - int(sc);
+            return QMargins(gap, 0, gap, gap);
         }
     }
     return QMargins();
@@ -930,12 +926,9 @@ QMargins QWindowsGeometryHint::frameOnPrimaryScreen(HWND hwnd)
 
 QMargins QWindowsGeometryHint::frame(DWORD style, DWORD exStyle, qreal dpi)
 {
-    if (QWindowsContext::user32dll.adjustWindowRectExForDpi == nullptr)
-        return frameOnPrimaryScreen(style, exStyle);
     RECT rect = {0,0,0,0};
     style &= ~DWORD(WS_OVERLAPPED); // Not permitted, see docs.
-    if (QWindowsContext::user32dll.adjustWindowRectExForDpi(&rect, style, FALSE, exStyle,
-                                                            unsigned(qRound(dpi))) == FALSE) {
+    if (AdjustWindowRectExForDpi(&rect, style, FALSE, exStyle, unsigned(qRound(dpi))) == FALSE) {
         qErrnoWarning("%s: AdjustWindowRectExForDpi failed", __FUNCTION__);
     }
     const QMargins result(qAbs(rect.left), qAbs(rect.top),
@@ -965,8 +958,7 @@ QMargins QWindowsGeometryHint::frame(const QWindow *w, const QRect &geometry,
 {
     if (!w->isTopLevel() || w->flags().testFlag(Qt::FramelessWindowHint))
         return {};
-    if (!QWindowsContext::user32dll.adjustWindowRectExForDpi
-        || QWindowsScreenManager::isSingleScreen()
+    if (QWindowsScreenManager::isSingleScreen()
         || !QWindowsContext::shouldHaveNonClientDpiScaling(w)) {
         return frameOnPrimaryScreen(style, exStyle);
     }
@@ -1417,8 +1409,7 @@ void QWindowsWindow::initialize()
         if (obtainedScreen && screen() != obtainedScreen)
             QWindowSystemInterface::handleWindowScreenChanged<QWindowSystemInterface::SynchronousDelivery>(w, obtainedScreen->screen());
     }
-    QWindowsWindow::setSavedDpi(QWindowsContext::user32dll.getDpiForWindow ?
-        QWindowsContext::user32dll.getDpiForWindow(handle()) : 96);
+    QWindowsWindow::setSavedDpi(GetDpiForWindow(handle()));
 }
 
 QSurfaceFormat QWindowsWindow::format() const