Taskbar notification: Hardened event name, proper detection of existing instance

ExplorerPatcher/TaskbarCenter.c

@@ -17,7 +17,7 @@ BOOL GetClientRectHook(HWND hWnd, LPRECT lpRect)
 	wchar_t wszClassName[100];
 	ZeroMemory(wszClassName, 100);
 	GetClassNameW(hWnd, wszClassName, 100);
-	if (!wcscmp(wszClassName, L"Shell_TrayWnd") || !wcscmp(wszClassName, L"Shell_SecondaryTrayWnd"))
+	if (!wcscmp(wszClassName, L"MSTaskListWClass"))
 	{
 		TaskbarCenter_Notify();
 	}
@@ -26,16 +26,16 @@ BOOL GetClientRectHook(HWND hWnd, LPRECT lpRect)
 
 HRESULT TaskbarCenter_Initialize(HMODULE hExplorer)
 {
-	// This is one of the methods called by explorer!CTaskListWnd::_RecomputeLayout
-	if (!VnPatchDelayIAT(hExplorer, "ext-ms-win-rtcore-ntuser-window-ext-l1-1-0.dll", "GetClientRect", GetClientRectHook))
+	if (!(hEvent = CreateEventW(NULL, TRUE, FALSE, TASKBAR_CHANGED_NOTIFICATION)))
 	{
 		return E_NOTIMPL;
 	}
-	if (!(hEvent = CreateEventW(NULL, TRUE, FALSE, TASKBAR_CHANGED_NOTIFICATION)))
+	if (FindWindowExW(NULL, NULL, L"Shell_TrayWnd", NULL))
 	{
 		return E_NOTIMPL;
 	}
-	if (GetLastError() == ERROR_ALREADY_EXISTS)
+	// This is one of the methods called by explorer!CTaskListWnd::_RecomputeLayout
+	if (!VnPatchDelayIAT(hExplorer, "ext-ms-win-rtcore-ntuser-window-ext-l1-1-0.dll", "GetClientRect", GetClientRectHook))
 	{
 		return E_NOTIMPL;
 	}

ExplorerPatcher/TaskbarCenter.h

@@ -4,7 +4,7 @@
 #include <Windows.h>
 #include <valinet/hooking/iatpatch.h>
 
-#define TASKBAR_CHANGED_NOTIFICATION L"Global\\ExplorerPatcher_TaskbarChangedNotification"
+#define TASKBAR_CHANGED_NOTIFICATION L"Global\\ExplorerPatcher_TaskbarChangedNotification_{B37553B7-425C-44F6-A04A-126849EE59CB}"
 
 HRESULT TaskbarCenter_Initialize(HMODULE);
 #endif