Transparent win32 window and text

Question

I am trying to make fullscreen transparent borderless window with text that displayed perfectly on top of it. The text background should be transparent but not the actual font face ofcourse. The problem is that I can only see TextOut displayed when I do not do SetWindowRgn. I have no idea what I am doing wrong :(

BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   HWND hWnd;
   hInst = hInstance;

   DWORD Flags1 = WS_EX_COMPOSITED | WS_EX_LAYERED | WS_EX_NOACTIVATE | WS_EX_TOPMOST | WS_EX_TRANSPARENT;
   DWORD Flags2 = WS_POPUP;

   hWnd = CreateWindowEx(Flags1, szWindowClass, szTitle, Flags2, 0, 0, 1920, 1200, 0, 0, hInstance, 0);

   if(!hWnd)return FALSE;

   HRGN GGG = CreateRectRgn(0, 0, 0, 0);
   SetWindowRgn(hWnd, GGG, false);

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   DeleteObject(GGG);

   return TRUE;
}

    case WM_PAINT:
    hdc = BeginPaint(hWnd, &ps);

    SetBkMode(hdc, TRANSPARENT);
    TextOut(hdc, 50, 50, L"MY TEXT", lstrlen(L"MY TEXT"));

    EndPaint(hWnd, &ps);

Answer 1

Solved this like this:

BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   HWND hWnd;
   hInst = hInstance;

   DWORD Flags1 = WS_EX_COMPOSITED | WS_EX_LAYERED | WS_EX_NOACTIVATE | WS_EX_TOPMOST | WS_EX_TRANSPARENT;
   DWORD Flags2 = WS_POPUP;

   hWnd = CreateWindowEx(Flags1, szWindowClass, szTitle, Flags2, 0, 0, 1920, 1200, 0, 0, hInstance, 0);

   if(!hWnd)return FALSE;

   HRGN GGG = CreateRectRgn(0, 0, 1920, 1200);
   InvertRgn(GetDC(hWnd), GGG);
   SetWindowRgn(hWnd, GGG, false);

   COLORREF RRR = RGB(255, 0, 255);
   SetLayeredWindowAttributes(hWnd, RRR, (BYTE)0, LWA_COLORKEY);

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   DeleteObject(GGG);

   return TRUE;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int wmId, wmEvent;
    PAINTSTRUCT ps;
    HDC hdc;
    RECT rect;

    switch (message)
    {
    case WM_ERASEBKGND:

        GetClientRect(hWnd, &rect);
        FillRect((HDC)wParam, &rect, CreateSolidBrush(RGB(255, 0, 255)));

        break;