diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0006ece..4d0a4fc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,6 +13,14 @@ if(NOT (CMAKE_BUILD_TYPE STREQUAL "Debug") AND NOT DEFINED CMAKE_INTERPROCEDURAL
     set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
 endif()
 
+if(NOT DEFINED CMAKE_DEBUG_POSTFIX)
+    if(WIN32)
+        set(CMAKE_DEBUG_POSTFIX d)
+    else()
+        set(CMAKE_DEBUG_POSTFIX _debug)
+    endif()
+endif()
+
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
diff --git a/examples/mainwindow/MainWindow.ui b/examples/mainwindow/MainWindow.ui
index 4e54cdb..0dc3e7e 100644
--- a/examples/mainwindow/MainWindow.ui
+++ b/examples/mainwindow/MainWindow.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>518</width>
-    <height>368</height>
+    <width>800</width>
+    <height>600</height>
    </rect>
   </property>
   <property name="windowTitle">
diff --git a/examples/mainwindow/mainwindow.cpp b/examples/mainwindow/mainwindow.cpp
index 3727086..c55dd65 100644
--- a/examples/mainwindow/mainwindow.cpp
+++ b/examples/mainwindow/mainwindow.cpp
@@ -61,7 +61,7 @@ void MainWindow::changeEvent(QEvent *event)
     bool shouldUpdate = false;
     if (event->type() == QEvent::WindowStateChange) {
 #ifdef Q_OS_WINDOWS
-        if (Utilities::isWin10OrGreater()) {
+        if (Utilities::isWindowFrameBorderVisible()) {
             if (isMaximized() || isFullScreen()) {
                 setContentsMargins(0, 0, 0, 0);
             } else if (!isMinimized()) {
@@ -91,7 +91,7 @@ void MainWindow::initFramelessHelperOnce()
 void MainWindow::resetContentsMargins()
 {
 #ifdef Q_OS_WINDOWS
-    if (Utilities::isWin10OrGreater()) {
+    if (Utilities::isWindowFrameBorderVisible()) {
         setContentsMargins(0, 1, 0, 0);
     }
 #endif
@@ -101,7 +101,7 @@ void MainWindow::paintEvent(QPaintEvent *event)
 {
     QMainWindow::paintEvent(event);
 #ifdef Q_OS_WINDOWS
-    if ((windowState() == Qt::WindowNoState) && Utilities::isWin10OrGreater() && !Utilities::isWin11OrGreater()) {
+    if ((windowState() == Qt::WindowNoState) && Utilities::isWindowFrameBorderVisible() && !Utilities::isWin11OrGreater()) {
         QPainter painter(this);
         painter.save();
         QPen pen = {};
diff --git a/examples/widget/widget.cpp b/examples/widget/widget.cpp
index ff5462b..bc114a5 100644
--- a/examples/widget/widget.cpp
+++ b/examples/widget/widget.cpp
@@ -111,7 +111,7 @@ void Widget::changeEvent(QEvent *event)
     bool shouldUpdate = false;
     if (event->type() == QEvent::WindowStateChange) {
 #ifdef Q_OS_WINDOWS
-        if (Utilities::isWin10OrGreater()) {
+        if (Utilities::isWindowFrameBorderVisible()) {
             if (isMaximized() || isFullScreen()) {
                 setContentsMargins(0, 0, 0, 0);
             } else if (!isMinimized()) {
@@ -133,7 +133,7 @@ void Widget::paintEvent(QPaintEvent *event)
 {
     QWidget::paintEvent(event);
 #ifdef Q_OS_WINDOWS
-    if ((windowState() == Qt::WindowNoState) && Utilities::isWin10OrGreater() && !Utilities::isWin11OrGreater()) {
+    if ((windowState() == Qt::WindowNoState) && Utilities::isWindowFrameBorderVisible() && !Utilities::isWin11OrGreater()) {
         QPainter painter(this);
         painter.save();
         QPen pen = {};
@@ -333,7 +333,7 @@ void Widget::updateSystemButtonIcons()
 void Widget::resetContentsMargins()
 {
 #ifdef Q_OS_WINDOWS
-    if (Utilities::isWin10OrGreater()) {
+    if (Utilities::isWindowFrameBorderVisible()) {
         setContentsMargins(0, 1, 0, 0);
     }
 #endif
diff --git a/framelesshelper.cpp b/framelesshelper.cpp
index 687049c..d023d89 100644
--- a/framelesshelper.cpp
+++ b/framelesshelper.cpp
@@ -23,12 +23,27 @@
  */
 
 #include "framelesshelper.h"
+#include <QtCore/qmutex.h>
 #include <QtGui/qevent.h>
 #include <QtGui/qwindow.h>
 #include "utilities.h"
 
 FRAMELESSHELPER_BEGIN_NAMESPACE
 
+struct UnixHelper
+{
+    QMutex mutex = {};
+    QWindowList acceptableWindows = {};
+
+    explicit UnixHelper() = default;
+    ~UnixHelper() = default;
+
+private:
+    Q_DISABLE_COPY_MOVE(UnixHelper)
+};
+
+Q_GLOBAL_STATIC(UnixHelper, g_unixHelper)
+
 FramelessHelper::FramelessHelper(QObject *parent) : QObject(parent) {}
 
 FramelessHelper::~FramelessHelper() = default;
@@ -39,6 +54,13 @@ void FramelessHelper::addWindow(QWindow *window)
     if (!window) {
         return;
     }
+    g_unixHelper()->mutex.lock();
+    if (g_unixHelper()->acceptableWindows.contains(window)) {
+        g_unixHelper()->mutex.unlock();
+        return;
+    }
+    g_unixHelper()->acceptableWindows.append(window);
+    g_unixHelper()->mutex.unlock();
     window->setFlags(window->flags() | Qt::FramelessWindowHint);
     window->installEventFilter(this);
 }
@@ -49,6 +71,13 @@ void FramelessHelper::removeWindow(QWindow *window)
     if (!window) {
         return;
     }
+    g_unixHelper()->mutex.lock();
+    if (!g_unixHelper()->acceptableWindows.contains(window)) {
+        g_unixHelper()->mutex.unlock();
+        return;
+    }
+    g_unixHelper()->acceptableWindows.removeAll(window);
+    g_unixHelper()->mutex.unlock();
     window->removeEventFilter(this);
     window->setFlags(window->flags() & ~Qt::FramelessWindowHint);
 }
@@ -70,6 +99,12 @@ bool FramelessHelper::eventFilter(QObject *object, QEvent *event)
         return false;
     }
     const auto window = qobject_cast<QWindow *>(object);
+    g_unixHelper()->mutex.lock();
+    if (!g_unixHelper()->acceptableWindows.contains(window)) {
+        g_unixHelper()->mutex.unlock();
+        return false;
+    }
+    g_unixHelper()->mutex.unlock();
     if (Utilities::isWindowFixedSize(window)) {
         return false;
     }
diff --git a/framelesshelper_global.h b/framelesshelper_global.h
index 91ddd99..8e41e7a 100644
--- a/framelesshelper_global.h
+++ b/framelesshelper_global.h
@@ -95,19 +95,9 @@ FRAMELESSHELPER_BEGIN_NAMESPACE
 
 Q_NAMESPACE_EXPORT(FRAMELESSHELPER_API)
 
-[[maybe_unused]] static constexpr const int kDefaultResizeBorderThicknessClassic = 4;
-[[maybe_unused]] static constexpr const int kDefaultResizeBorderThicknessAero = 8;
+[[maybe_unused]] static constexpr const int kDefaultResizeBorderThickness = 8;
 [[maybe_unused]] static constexpr const int kDefaultCaptionHeight = 23;
 [[maybe_unused]] static constexpr const int kDefaultTitleBarHeight = 30;
 [[maybe_unused]] static constexpr const int kDefaultWindowFrameBorderThickness = 1;
 
-enum class DwmColorizationArea : int
-{
-    None = 0,
-    StartMenu_TaskBar_ActionCenter = 1,
-    TitleBar_WindowBorder = 2,
-    All = 3
-};
-Q_ENUM_NS(DwmColorizationArea)
-
 FRAMELESSHELPER_END_NAMESPACE
diff --git a/framelesshelper_win32.cpp b/framelesshelper_win32.cpp
index b47bea3..1fc1717 100644
--- a/framelesshelper_win32.cpp
+++ b/framelesshelper_win32.cpp
@@ -30,37 +30,37 @@
 #include <QtCore/qcoreapplication.h>
 #include <QtGui/qwindow.h>
 #include "framelesswindowsmanager.h"
-#include "framelesswindowsmanager_p.h"
 #include "utilities.h"
 #include "framelesshelper_windows.h"
 
 FRAMELESSHELPER_BEGIN_NAMESPACE
 
-struct FramelessHelperWinData
+struct Win32Helper
 {
     QMutex mutex = {};
-    QScopedPointer<FramelessHelperWin> instance;
-    QList<WId> acceptableWinIds = {};
+    QScopedPointer<FramelessHelperWin> nativeEventFilter;
+    QWindowList acceptableWindows = {};
+    QHash<WId, QWindow *> windowMapping = {};
     QHash<HWND, WNDPROC> qtWindowProcs = {};
 
-    explicit FramelessHelperWinData() = default;
-    ~FramelessHelperWinData() = default;
+    explicit Win32Helper() = default;
+    ~Win32Helper() = default;
 
 private:
-    Q_DISABLE_COPY_MOVE(FramelessHelperWinData)
+    Q_DISABLE_COPY_MOVE(Win32Helper)
 };
 
-Q_GLOBAL_STATIC(FramelessHelperWinData, g_helper)
+Q_GLOBAL_STATIC(Win32Helper, g_win32Helper)
 
 [[nodiscard]] static inline LRESULT CALLBACK HookWindowProc
     (const HWND hWnd, const UINT uMsg, const WPARAM wParam, const LPARAM lParam)
 {
-    g_helper()->mutex.lock();
-    if (!g_helper()->qtWindowProcs.contains(hWnd)) {
-        g_helper()->mutex.unlock();
+    g_win32Helper()->mutex.lock();
+    if (!g_win32Helper()->qtWindowProcs.contains(hWnd)) {
+        g_win32Helper()->mutex.unlock();
         return DefWindowProcW(hWnd, uMsg, wParam, lParam);
     }
-    g_helper()->mutex.unlock();
+    g_win32Helper()->mutex.unlock();
     const auto winId = reinterpret_cast<WId>(hWnd);
     const auto getGlobalPosFromMouse = [lParam]() -> QPointF {
         return {qreal(GET_X_LPARAM(lParam)), qreal(GET_Y_LPARAM(lParam))};
@@ -75,7 +75,7 @@ Q_GLOBAL_STATIC(FramelessHelperWinData, g_helper)
         const int frameSizeX = Utilities::getResizeBorderThickness(winId, true, true);
         const int frameSizeY = Utilities::getResizeBorderThickness(winId, false, true);
         const int titleBarHeight = Utilities::getTitleBarHeight(winId, true);
-        const int horizontalOffset = ((maxOrFull || !Utilities::isWin10OrGreater()) ? 0 : frameSizeX);
+        const int horizontalOffset = ((maxOrFull || !Utilities::isWindowFrameBorderVisible()) ? 0 : frameSizeX);
         const int verticalOffset = (maxOrFull ? titleBarHeight : (titleBarHeight - frameSizeY));
         return {qreal(rect.left + horizontalOffset), qreal(rect.top + verticalOffset)};
     };
@@ -108,9 +108,9 @@ Q_GLOBAL_STATIC(FramelessHelperWinData, g_helper)
         // entering Qt's own handling logic.
         return 0; // Return 0 means we have handled this event.
     }
-    g_helper()->mutex.lock();
-    const WNDPROC originalWindowProc = g_helper()->qtWindowProcs.value(hWnd);
-    g_helper()->mutex.unlock();
+    g_win32Helper()->mutex.lock();
+    const WNDPROC originalWindowProc = g_win32Helper()->qtWindowProcs.value(hWnd);
+    g_win32Helper()->mutex.unlock();
     Q_ASSERT(originalWindowProc);
     if (originalWindowProc) {
         // Hand over to Qt's original window proc function for events we are not
@@ -128,8 +128,8 @@ Q_GLOBAL_STATIC(FramelessHelperWinData, g_helper)
         return false;
     }
     const auto hwnd = reinterpret_cast<HWND>(winId);
-    QMutexLocker locker(&g_helper()->mutex);
-    if (g_helper()->qtWindowProcs.contains(hwnd)) {
+    QMutexLocker locker(&g_win32Helper()->mutex);
+    if (g_win32Helper()->qtWindowProcs.contains(hwnd)) {
         return false;
     }
     SetLastError(ERROR_SUCCESS);
@@ -144,7 +144,7 @@ Q_GLOBAL_STATIC(FramelessHelperWinData, g_helper)
         qWarning() << Utilities::getSystemErrorMessage(QStringLiteral("SetWindowLongPtrW"));
         return false;
     }
-    g_helper()->qtWindowProcs.insert(hwnd, originalWindowProc);
+    g_win32Helper()->qtWindowProcs.insert(hwnd, originalWindowProc);
     return true;
 }
 
@@ -155,11 +155,11 @@ Q_GLOBAL_STATIC(FramelessHelperWinData, g_helper)
         return false;
     }
     const auto hwnd = reinterpret_cast<HWND>(winId);
-    QMutexLocker locker(&g_helper()->mutex);
-    if (!g_helper()->qtWindowProcs.contains(hwnd)) {
+    QMutexLocker locker(&g_win32Helper()->mutex);
+    if (!g_win32Helper()->qtWindowProcs.contains(hwnd)) {
         return false;
     }
-    const WNDPROC originalWindowProc = g_helper()->qtWindowProcs.value(hwnd);
+    const WNDPROC originalWindowProc = g_win32Helper()->qtWindowProcs.value(hwnd);
     Q_ASSERT(originalWindowProc);
     if (!originalWindowProc) {
         return false;
@@ -169,7 +169,7 @@ Q_GLOBAL_STATIC(FramelessHelperWinData, g_helper)
         qWarning() << Utilities::getSystemErrorMessage(QStringLiteral("SetWindowLongPtrW"));
         return false;
     }
-    g_helper()->qtWindowProcs.remove(hwnd);
+    g_win32Helper()->qtWindowProcs.remove(hwnd);
     return true;
 }
 
@@ -186,18 +186,19 @@ void FramelessHelperWin::addWindow(QWindow *window)
     if (!window) {
         return;
     }
-    const WId winId = window->winId();
-    g_helper()->mutex.lock();
-    if (g_helper()->acceptableWinIds.contains(winId)) {
-        g_helper()->mutex.unlock();
+    g_win32Helper()->mutex.lock();
+    if (g_win32Helper()->acceptableWindows.contains(window)) {
+        g_win32Helper()->mutex.unlock();
         return;
     }
-    g_helper()->acceptableWinIds.append(winId);
-    if (g_helper()->instance.isNull()) {
-        g_helper()->instance.reset(new FramelessHelperWin);
-        qApp->installNativeEventFilter(g_helper()->instance.data());
+    g_win32Helper()->acceptableWindows.append(window);
+    const WId winId = window->winId();
+    g_win32Helper()->windowMapping.insert(winId, window);
+    if (g_win32Helper()->nativeEventFilter.isNull()) {
+        g_win32Helper()->nativeEventFilter.reset(new FramelessHelperWin);
+        qApp->installNativeEventFilter(g_win32Helper()->nativeEventFilter.data());
     }
-    g_helper()->mutex.unlock();
+    g_win32Helper()->mutex.unlock();
     Utilities::fixupQtInternals(winId);
     Utilities::updateInternalWindowFrameMargins(window, true);
     Utilities::updateWindowFrameMargins(winId, false);
@@ -214,14 +215,15 @@ void FramelessHelperWin::removeWindow(QWindow *window)
     if (!window) {
         return;
     }
-    const WId winId = window->winId();
-    g_helper()->mutex.lock();
-    if (!g_helper()->acceptableWinIds.contains(winId)) {
-        g_helper()->mutex.unlock();
+    g_win32Helper()->mutex.lock();
+    if (!g_win32Helper()->acceptableWindows.contains(window)) {
+        g_win32Helper()->mutex.unlock();
         return;
     }
-    g_helper()->acceptableWinIds.removeAll(winId);
-    g_helper()->mutex.unlock();
+    g_win32Helper()->acceptableWindows.removeAll(window);
+    const WId winId = window->winId();
+    g_win32Helper()->windowMapping.remove(winId);
+    g_win32Helper()->mutex.unlock();
     if (!uninstallWindowHook(winId)) {
         qWarning() << "Failed to un-hook the window proc function.";
     }
@@ -250,19 +252,13 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         return false;
     }
     const WId winId = reinterpret_cast<WId>(msg->hwnd);
-    g_helper()->mutex.lock();
-    if (!g_helper()->acceptableWinIds.contains(winId)) {
-        g_helper()->mutex.unlock();
+    g_win32Helper()->mutex.lock();
+    if (!g_win32Helper()->windowMapping.contains(winId)) {
+        g_win32Helper()->mutex.unlock();
         return false;
     }
-    g_helper()->mutex.unlock();
-    const FramelessManagerPrivate * const manager = FramelessManagerPrivate::instance();
-    const QUuid id = manager->findIdByWinId(winId);
-    Q_ASSERT(!id.isNull());
-    if (id.isNull()) {
-        return false;
-    }
-    QWindow * const window = manager->findWindowById(id);
+    QWindow * const window = g_win32Helper()->windowMapping.value(winId);
+    g_win32Helper()->mutex.unlock();
     Q_ASSERT(window);
     if (!window) {
         return false;
@@ -359,7 +355,7 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         const auto clientRect = ((static_cast<BOOL>(msg->wParam) == FALSE)
                                  ? reinterpret_cast<LPRECT>(msg->lParam)
                                  : &(reinterpret_cast<LPNCCALCSIZE_PARAMS>(msg->lParam))->rgrc[0]);
-        if (Utilities::isWin10OrGreater()) {
+        if (Utilities::isWindowFrameBorderVisible()) {
             // Store the original top before the default window proc applies the default frame.
             const LONG originalTop = clientRect->top;
             // Apply the default frame.
@@ -385,7 +381,7 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
             // a window when it's maximized unless you restore it).
             const int frameSizeY = Utilities::getResizeBorderThickness(winId, false, true);
             clientRect->top += frameSizeY;
-            if (!Utilities::isWin10OrGreater()) {
+            if (!Utilities::isWindowFrameBorderVisible()) {
                 clientRect->bottom -= frameSizeY;
                 const int frameSizeX = Utilities::getResizeBorderThickness(winId, true, true);
                 clientRect->left += frameSizeX;
@@ -598,8 +594,8 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         const bool full = Utilities::isFullScreen(winId);
         const int frameSizeY = Utilities::getResizeBorderThickness(winId, false, true);
         const bool isTop = (localPos.y < frameSizeY);
-        const bool isTitleBar = false; // ### TODO
-        if (Utilities::isWin10OrGreater()) {
+        static constexpr const bool isTitleBar = false;
+        if (Utilities::isWindowFrameBorderVisible()) {
             // This will handle the left, right and bottom parts of the frame
             // because we didn't change them.
             const LRESULT originalRet = DefWindowProcW(msg->hwnd, WM_NCHITTEST, 0, msg->lParam);
@@ -712,7 +708,7 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
     default:
         break;
     }
-    if (!Utilities::isWin10OrGreater()) {
+    if (!Utilities::isWindowFrameBorderVisible()) {
         switch (msg->message) {
         case WM_NCUAHDRAWCAPTION:
         case WM_NCUAHDRAWFRAME: {
diff --git a/framelessquickhelper.cpp b/framelessquickhelper.cpp
index 48d4443..a28e2ae 100644
--- a/framelessquickhelper.cpp
+++ b/framelessquickhelper.cpp
@@ -78,7 +78,7 @@ qreal FramelessQuickUtils::titleBarHeight()
 bool FramelessQuickUtils::frameBorderVisible()
 {
 #ifdef Q_OS_WINDOWS
-    return (Utilities::isWin10OrGreater() && !Utilities::isWin11OrGreater());
+    return (Utilities::isWindowFrameBorderVisible() && !Utilities::isWin11OrGreater());
 #else
     return false;
 #endif
diff --git a/framelessquickhelper.h b/framelessquickhelper.h
index 0f35076..eef8c6e 100644
--- a/framelessquickhelper.h
+++ b/framelessquickhelper.h
@@ -41,6 +41,9 @@ class FRAMELESSHELPER_API FramelessQuickHelper : public QObject
 #ifdef QML_NAMED_ELEMENT
     QML_NAMED_ELEMENT(FramelessHelper)
 #endif
+#ifdef QML_SINGLETON
+    QML_SINGLETON
+#endif
 
 public:
     explicit FramelessQuickHelper(QObject *parent = nullptr);
@@ -56,6 +59,9 @@ class FRAMELESSHELPER_API FramelessQuickUtils : public QObject
     Q_DISABLE_COPY_MOVE(FramelessQuickUtils)
 #ifdef QML_NAMED_ELEMENT
     QML_NAMED_ELEMENT(FramelessUtils)
+#endif
+#ifdef QML_SINGLETON
+    QML_SINGLETON
 #endif
     Q_PROPERTY(qreal titleBarHeight READ titleBarHeight CONSTANT FINAL)
     Q_PROPERTY(bool frameBorderVisible READ frameBorderVisible CONSTANT FINAL)
diff --git a/utilities.cpp b/utilities.cpp
index 76ccace..02072e5 100644
--- a/utilities.cpp
+++ b/utilities.cpp
@@ -26,8 +26,6 @@
 
 FRAMELESSHELPER_BEGIN_NAMESPACE
 
-static constexpr const int g_resizeBorderThickness = kDefaultResizeBorderThicknessAero;
-
 Qt::CursorShape Utilities::calculateCursorShape(const QWindow *window, const QPointF &pos)
 {
     Q_ASSERT(window);
@@ -37,18 +35,18 @@ Qt::CursorShape Utilities::calculateCursorShape(const QWindow *window, const QPo
     if (window->visibility() != QWindow::Windowed) {
         return Qt::ArrowCursor;
     }
-    if (((pos.x() < g_resizeBorderThickness) && (pos.y() < g_resizeBorderThickness))
-        || ((pos.x() >= (window->width() - g_resizeBorderThickness)) && (pos.y() >= (window->height() - g_resizeBorderThickness)))) {
+    if (((pos.x() < kDefaultResizeBorderThickness) && (pos.y() < kDefaultResizeBorderThickness))
+        || ((pos.x() >= (window->width() - kDefaultResizeBorderThickness)) && (pos.y() >= (window->height() - kDefaultResizeBorderThickness)))) {
         return Qt::SizeFDiagCursor;
     }
-    if (((pos.x() >= (window->width() - g_resizeBorderThickness)) && (pos.y() < g_resizeBorderThickness))
-        || ((pos.x() < g_resizeBorderThickness) && (pos.y() >= (window->height() - g_resizeBorderThickness)))) {
+    if (((pos.x() >= (window->width() - kDefaultResizeBorderThickness)) && (pos.y() < kDefaultResizeBorderThickness))
+        || ((pos.x() < kDefaultResizeBorderThickness) && (pos.y() >= (window->height() - kDefaultResizeBorderThickness)))) {
         return Qt::SizeBDiagCursor;
     }
-    if ((pos.x() < g_resizeBorderThickness) || (pos.x() >= (window->width() - g_resizeBorderThickness))) {
+    if ((pos.x() < kDefaultResizeBorderThickness) || (pos.x() >= (window->width() - kDefaultResizeBorderThickness))) {
         return Qt::SizeHorCursor;
     }
-    if ((pos.y() < g_resizeBorderThickness) || (pos.y() >= (window->height() - g_resizeBorderThickness))) {
+    if ((pos.y() < kDefaultResizeBorderThickness) || (pos.y() >= (window->height() - kDefaultResizeBorderThickness))) {
         return Qt::SizeVerCursor;
     }
     return Qt::ArrowCursor;
@@ -64,16 +62,16 @@ Qt::Edges Utilities::calculateWindowEdges(const QWindow *window, const QPointF &
         return {};
     }
     Qt::Edges edges = {};
-    if (pos.x() < g_resizeBorderThickness) {
+    if (pos.x() < kDefaultResizeBorderThickness) {
         edges |= Qt::LeftEdge;
     }
-    if (pos.x() >= (window->width() - g_resizeBorderThickness)) {
+    if (pos.x() >= (window->width() - kDefaultResizeBorderThickness)) {
         edges |= Qt::RightEdge;
     }
-    if (pos.y() < g_resizeBorderThickness) {
+    if (pos.y() < kDefaultResizeBorderThickness) {
         edges |= Qt::TopEdge;
     }
-    if (pos.y() >= (window->height() - g_resizeBorderThickness)) {
+    if (pos.y() >= (window->height() - kDefaultResizeBorderThickness)) {
         edges |= Qt::BottomEdge;
     }
     return edges;
diff --git a/utilities.h b/utilities.h
index 86d3bda..4247554 100644
--- a/utilities.h
+++ b/utilities.h
@@ -29,6 +29,17 @@
 
 FRAMELESSHELPER_BEGIN_NAMESPACE
 
+#ifdef Q_OS_WINDOWS
+enum class DwmColorizationArea : int
+{
+    None = 0,
+    StartMenu_TaskBar_ActionCenter = 1,
+    TitleBar_WindowBorder = 2,
+    All = 3
+};
+Q_ENUM_NS(DwmColorizationArea)
+#endif
+
 namespace Utilities
 {
 
@@ -66,6 +77,7 @@ FRAMELESSHELPER_API void showSystemMenu(const WId winId, const QPointF &pos);
 [[nodiscard]] FRAMELESSHELPER_API QColor getFrameBorderColor(const bool active);
 FRAMELESSHELPER_API void updateWindowFrameBorderColor(const WId winId, const bool dark);
 FRAMELESSHELPER_API void fixupQtInternals(const WId winId);
+[[nodiscard]] FRAMELESSHELPER_API bool isWindowFrameBorderVisible();
 #endif // Q_OS_WINDOWS
 
 } // namespace Utilities
diff --git a/utilities_win32.cpp b/utilities_win32.cpp
index ce5b654..5e473e4 100644
--- a/utilities_win32.cpp
+++ b/utilities_win32.cpp
@@ -46,6 +46,8 @@ Q_DECLARE_METATYPE(QMargins)
 
 FRAMELESSHELPER_BEGIN_NAMESPACE
 
+static const QString successErrorText = QStringLiteral("The operation completed successfully.");
+
 #if (QT_VERSION < QT_VERSION_CHECK(5, 9, 0))
 [[nodiscard]] static inline bool isWindowsVersionOrGreater(const DWORD dwMajor, const DWORD dwMinor, const DWORD dwBuild)
 {
@@ -71,17 +73,21 @@ FRAMELESSHELPER_BEGIN_NAMESPACE
         return {};
     }
     if (code == ERROR_SUCCESS) {
-        return {};
+        return successErrorText;
     }
     LPWSTR buf = nullptr;
     if (FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                        nullptr, code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), reinterpret_cast<LPWSTR>(&buf), 0, nullptr) == 0) {
-        return {};
+        return QStringLiteral("FormatMessageW() returned empty string.");
     }
-    const QString message = QStringLiteral("Function %1() failed with error code %2: %3.")
-                                .arg(function, QString::number(code), QString::fromWCharArray(buf));
+    QString errorText = QString::fromWCharArray(buf);
     LocalFree(buf);
-    return message;
+    buf = nullptr;
+    errorText = errorText.trimmed();
+    errorText.remove(QStringLiteral("\\r"));
+    errorText.replace(QStringLiteral("\\n"), QStringLiteral("\n"));
+    return QStringLiteral("Function \"%1()\" failed with error code %2: %3.")
+                                 .arg(function, QString::number(code), errorText);
 }
 
 [[nodiscard]] static inline QString __getSystemErrorMessage(const QString &function, const HRESULT hr)
@@ -91,7 +97,7 @@ FRAMELESSHELPER_BEGIN_NAMESPACE
         return {};
     }
     if (SUCCEEDED(hr)) {
-        return {};
+        return successErrorText;
     }
     const DWORD dwError = HRESULT_CODE(hr);
     return __getSystemErrorMessage(function, dwError);
@@ -248,7 +254,7 @@ void Utilities::updateWindowFrameMargins(const WId winId, const bool reset)
         if (reset) {
             return {0, 0, 0, 0};
         }
-        if (isWin10OrGreater()) {
+        if (isWindowFrameBorderVisible()) {
             return {0, static_cast<int>(getTitleBarHeight(winId, true)), 0, 0};
         } else {
             return {1, 1, 1, 1};
@@ -275,7 +281,7 @@ void Utilities::updateInternalWindowFrameMargins(QWindow *window, const bool ena
             return {};
         }
         const int titleBarHeight = getTitleBarHeight(winId, true);
-        if (isWin10OrGreater()) {
+        if (isWindowFrameBorderVisible()) {
             return {0, -titleBarHeight, 0, 0};
         } else {
             const int frameSizeX = getResizeBorderThickness(winId, true, true);
@@ -286,17 +292,14 @@ void Utilities::updateInternalWindowFrameMargins(QWindow *window, const bool ena
     const QVariant marginsVar = QVariant::fromValue(margins);
     window->setProperty("_q_windowsCustomMargins", marginsVar);
 #if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
-    QPlatformWindow *platformWindow = window->handle();
-    if (platformWindow) {
+    if (QPlatformWindow *platformWindow = window->handle()) {
         QGuiApplication::platformNativeInterface()->setWindowProperty(platformWindow, QStringLiteral("WindowsCustomMargins"), marginsVar);
     } else {
         qWarning() << "Failed to retrieve the platform window.";
         return;
     }
 #else
-    auto *platformWindow = dynamic_cast<QNativeInterface::Private::QWindowsWindow *>(
-        window->handle());
-    if (platformWindow) {
+    if (const auto platformWindow = dynamic_cast<QNativeInterface::Private::QWindowsWindow *>(window->handle())) {
         platformWindow->setCustomMargins(margins);
     } else {
         qWarning() << "Failed to retrieve the platform window.";
@@ -866,4 +869,20 @@ void Utilities::startSystemResize(QWindow *window, const Qt::Edges edges)
 #endif
 }
 
+bool Utilities::isWindowFrameBorderVisible()
+{
+    static const bool result = []() -> bool {
+        // If we preserve the window frame border on systems before Windows 10,
+        // the window will look rather ugly and I guess no one would like to see
+        // such weired windows. If you really want to know what the window look
+        // like in such situations, just comment out the following IF statement
+        // and run your application on Windows 7/8/8.1.
+        if (!isWin10OrGreater()) {
+            return false;
+        }
+        return !qEnvironmentVariableIsSet("FRAMELESSHELPER_HIDE_FRAME_BORDER");
+    }();
+    return result;
+}
+
 FRAMELESSHELPER_END_NAMESPACE