diff --git a/README.md b/README.md
index bcadc2c0..8463813d 100644
--- a/README.md
+++ b/README.md
@@ -1,11 +1,11 @@
-This is Qt 6.7.2 **qtbase module** backport that runs on Windows 7/8. The repository contains patched source files from the qtbase module. 
+This is Qt 6.7.3 **qtbase module** backport that runs on Windows 7/8. The repository contains patched source files from the qtbase module. 
 Approach is based on this [forum thread](https://forum.qt.io/topic/133002/qt-creator-6-0-1-and-qt-6-2-2-running-on-windows-7/60) but better: many improvements amongst important fallbacks to default Qt 6 behaviour when running on newer Windows.
 
 - After replacing qtbase source files with the patched ones from this repository, you can compile Qt yourself using compiler and build options you need.
-- You can use our [compile_win.pl](https://github.com/crystalidea/qt-build-tools/tree/master/6.7.2) build script (uses Visual C++ 2022 with OpenSSL 3.0.13 statically linked)
+- You can use our [compile_win.pl](https://github.com/crystalidea/qt-build-tools/tree/master/6.7.3) build script (uses Visual C++ 2022 with OpenSSL 3.0.13 statically linked)
 - You can download our [prebuild Qt dlls](https://github.com/crystalidea/qt6windows7/releases) which also have Qt Designer binary for demonstration
 
-**Qt 6.7.2 designer running on Windows 7**:
+**Qt 6.7.3 designer running on Windows 7**:
 
 ![image](https://github.com/crystalidea/qt6windows7/assets/2600624/41f4291a-082a-41e8-a09d-c3b9e7f36e9e)
 
diff --git a/designer.png b/designer.png
new file mode 100644
index 00000000..95cf5664
Binary files /dev/null and b/designer.png differ
diff --git a/qtbase/src/gui/rhi/qrhid3d11.cpp b/qtbase/src/gui/rhi/qrhid3d11.cpp
index 7d2a99ed..4f015668 100644
--- a/qtbase/src/gui/rhi/qrhid3d11.cpp
+++ b/qtbase/src/gui/rhi/qrhid3d11.cpp
@@ -2872,7 +2872,7 @@ void QRhiD3D11::executeCommandBuffer(QD3D11CommandBuffer *cbD)
             break;
         case QD3D11CommandBuffer::Command::Draw:
             if (cmd.args.draw.ps) {
-                if (cmd.args.draw.instanceCount == 1)
+                if (cmd.args.draw.instanceCount == 1 && cmd.args.draw.firstInstance == 0)
                     context->Draw(cmd.args.draw.vertexCount, cmd.args.draw.firstVertex);
                 else
                     context->DrawInstanced(cmd.args.draw.vertexCount, cmd.args.draw.instanceCount,
@@ -2883,7 +2883,7 @@ void QRhiD3D11::executeCommandBuffer(QD3D11CommandBuffer *cbD)
             break;
         case QD3D11CommandBuffer::Command::DrawIndexed:
             if (cmd.args.drawIndexed.ps) {
-                if (cmd.args.drawIndexed.instanceCount == 1)
+                if (cmd.args.drawIndexed.instanceCount == 1 && cmd.args.drawIndexed.firstInstance == 0)
                     context->DrawIndexed(cmd.args.drawIndexed.indexCount, cmd.args.drawIndexed.firstIndex,
                                          cmd.args.drawIndexed.vertexOffset);
                 else
diff --git a/qtbase/src/plugins/platforms/windows/qwindowsdrag.cpp b/qtbase/src/plugins/platforms/windows/qwindowsdrag.cpp
index 072906c5..b4439b46 100644
--- a/qtbase/src/plugins/platforms/windows/qwindowsdrag.cpp
+++ b/qtbase/src/plugins/platforms/windows/qwindowsdrag.cpp
@@ -256,8 +256,9 @@ void QWindowsOleDropSource::createCursors()
         if (const QScreen *primaryScreen = QGuiApplication::primaryScreen())
             platformScreen = primaryScreen->handle();
     }
-    Q_ASSERT(platformScreen);
-    QPlatformCursor *platformCursor = platformScreen->cursor();
+    QPlatformCursor *platformCursor = nullptr;
+    if (platformScreen)
+        platformCursor = platformScreen->cursor();
 
     if (GetSystemMetrics (SM_REMOTESESSION) != 0) {
         /* Workaround for RDP issues with large cursors.
@@ -274,7 +275,7 @@ void QWindowsOleDropSource::createCursors()
         hotSpotScaleFactor = QHighDpiScaling::factor(platformScreen);
         pixmapScaleFactor = hotSpotScaleFactor / pixmap.devicePixelRatio();
     }
-    QPixmap scaledPixmap = qFuzzyCompare(pixmapScaleFactor, 1.0)
+    QPixmap scaledPixmap = (!hasPixmap || qFuzzyCompare(pixmapScaleFactor, 1.0))
         ? pixmap
         :  pixmap.scaled((QSizeF(pixmap.size()) * pixmapScaleFactor).toSize(),
                          Qt::KeepAspectRatio, Qt::SmoothTransformation);
diff --git a/qtbase/src/plugins/platforms/windows/qwindowsscreen.cpp b/qtbase/src/plugins/platforms/windows/qwindowsscreen.cpp
index 23486b24..3552e21d 100644
--- a/qtbase/src/plugins/platforms/windows/qwindowsscreen.cpp
+++ b/qtbase/src/plugins/platforms/windows/qwindowsscreen.cpp
@@ -142,6 +142,18 @@ struct DiRegKeyHandleTraits
 
 using DiRegKeyHandle = QUniqueHandle<DiRegKeyHandleTraits>;
 
+struct DevInfoHandleTraits
+{
+    using Type = HDEVINFO;
+    static Type invalidValue()
+    {
+        return reinterpret_cast<HDEVINFO>(INVALID_HANDLE_VALUE);
+    }
+    static bool close(Type handle) { return SetupDiDestroyDeviceInfoList(handle) == TRUE; }
+};
+
+using DevInfoHandle = QUniqueHandle<DevInfoHandleTraits>;
+
 }
 
 static void setMonitorDataFromSetupApi(QWindowsScreenData &data,
@@ -191,13 +203,16 @@ static void setMonitorDataFromSetupApi(QWindowsScreenData &data,
         constexpr GUID GUID_DEVINTERFACE_MONITOR = {
             0xe6f07b5f, 0xee97, 0x4a90, { 0xb0, 0x76, 0x33, 0xf5, 0x7b, 0xf4, 0xea, 0xa7 }
         };
-        const HDEVINFO devInfo = SetupDiGetClassDevs(&GUID_DEVINTERFACE_MONITOR, nullptr, nullptr,
-                                                     DIGCF_DEVICEINTERFACE);
+        const DevInfoHandle devInfo{ SetupDiGetClassDevs(
+                &GUID_DEVINTERFACE_MONITOR, nullptr, nullptr, DIGCF_DEVICEINTERFACE) };
+
+        if (!devInfo.isValid())
+            continue;
 
         SP_DEVICE_INTERFACE_DATA deviceInterfaceData{};
         deviceInterfaceData.cbSize = sizeof(deviceInterfaceData);
 
-        if (!SetupDiOpenDeviceInterfaceW(devInfo, deviceName.monitorDevicePath, DIODI_NO_ADD,
+        if (!SetupDiOpenDeviceInterfaceW(devInfo.get(), deviceName.monitorDevicePath, DIODI_NO_ADD,
                                          &deviceInterfaceData)) {
             qCWarning(lcQpaScreen)
                     << u"Unable to open monitor interface to %1:"_s.arg(data.deviceName)
@@ -206,7 +221,7 @@ static void setMonitorDataFromSetupApi(QWindowsScreenData &data,
         }
 
         DWORD requiredSize{ 0 };
-        if (SetupDiGetDeviceInterfaceDetailW(devInfo, &deviceInterfaceData, nullptr, 0,
+        if (SetupDiGetDeviceInterfaceDetailW(devInfo.get(), &deviceInterfaceData, nullptr, 0,
                                              &requiredSize, nullptr)
             || GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
             continue;
@@ -217,7 +232,7 @@ static void setMonitorDataFromSetupApi(QWindowsScreenData &data,
         devicePath->cbSize = sizeof(std::remove_pointer_t<decltype(devicePath)>);
         SP_DEVINFO_DATA deviceInfoData{};
         deviceInfoData.cbSize = sizeof(deviceInfoData);
-        if (!SetupDiGetDeviceInterfaceDetailW(devInfo, &deviceInterfaceData, devicePath,
+        if (!SetupDiGetDeviceInterfaceDetailW(devInfo.get(), &deviceInterfaceData, devicePath,
                                               requiredSize, nullptr, &deviceInfoData)) {
             qCDebug(lcQpaScreen) << u"Unable to get monitor metadata for %1:"_s.arg(data.deviceName)
                                  << QSystemError::windowsString();
@@ -225,7 +240,7 @@ static void setMonitorDataFromSetupApi(QWindowsScreenData &data,
         }
 
         const DiRegKeyHandle edidRegistryKey{ SetupDiOpenDevRegKey(
-                devInfo, &deviceInfoData, DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_READ) };
+                devInfo.get(), &deviceInfoData, DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_READ) };
 
         if (!edidRegistryKey.isValid())
             continue;
diff --git a/qtbase/src/plugins/platforms/windows/qwindowswindow.cpp b/qtbase/src/plugins/platforms/windows/qwindowswindow.cpp
index 59e5ace4..b4cd8a8e 100644
--- a/qtbase/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/qtbase/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -35,6 +35,7 @@
 
 #include <QtCore/qdebug.h>
 #include <QtCore/qlibraryinfo.h>
+#include <QtCore/qoperatingsystemversion.h>
 
 #include <dwmapi.h>
 
@@ -2176,11 +2177,8 @@ void QWindowsWindow::setGeometry(const QRect &rectIn)
         const QMargins margins = frameMargins();
         rect.moveTopLeft(rect.topLeft() + QPoint(margins.left(), margins.top()));
     }
-
     if (m_windowState & Qt::WindowMinimized)
         m_data.geometry = rect; // Otherwise set by handleGeometryChange() triggered by event.
-    else
-        setWindowState(Qt::WindowNoState);// Update window state to WindowNoState unless minimized
 
     if (m_data.hwnd) {
         // A ResizeEvent with resulting geometry will be sent. If we cannot
@@ -2490,6 +2488,12 @@ QWindowsWindowData QWindowsWindow::setWindowFlags_sys(Qt::WindowFlags wt,
     return result;
 }
 
+inline bool QWindowsBaseWindow::hasMaximumSize() const
+{
+    const auto maximumSize = window()->maximumSize();
+    return maximumSize.width() != QWINDOWSIZE_MAX || maximumSize.height() != QWINDOWSIZE_MAX;
+}
+
 void QWindowsWindow::handleWindowStateChange(Qt::WindowStates state)
 {
     qCDebug(lcQpaWindow) << __FUNCTION__ << this << window()
@@ -2506,6 +2510,21 @@ void QWindowsWindow::handleWindowStateChange(Qt::WindowStates state)
             GetWindowPlacement(m_data.hwnd, &windowPlacement);
             const RECT geometry = RECTfromQRect(m_data.restoreGeometry);
             windowPlacement.rcNormalPosition = geometry;
+
+            // A bug in windows 10 grows
+            // - ptMaxPosition.x by the task bar's width, if it's on the left
+            // - ptMaxPosition.y by the task bar's height, if it's on the top
+            // each time GetWindowPlacement() is called.
+            // The offset of the screen's left edge (as per frameMargins_sys().left()) is ignored.
+            // => Check for windows 10 and correct.
+            static const auto windows11 = QOperatingSystemVersion::Windows11_21H2;
+            static const bool isWindows10 = QOperatingSystemVersion::current() < windows11;
+            if (isWindows10 && hasMaximumSize()) {
+                const QMargins margins = frameMargins_sys();
+                const QPoint topLeft = window()->screen()->geometry().topLeft();
+                windowPlacement.ptMaxPosition = POINT{ topLeft.x() - margins.left(), topLeft.y() };
+            }
+
             // Even if the window is hidden, windowPlacement's showCmd is not SW_HIDE, so change it
             // manually to avoid unhiding a hidden window with the subsequent call to
             // SetWindowPlacement().