CreateWindow проблема с созданием окна

#include <Windows.h>
const wchar_t * ClassName = L"Window1";
const wchar_t * WindowName = L"Window1";
LRESULT CALLBACK WndProc1(HWND hwnd, UINT Comand, WPARAM Wparam, LPARAM Lparam);
int WINAPI WinMain(HINSTANCE hInst, HINSTANCE phInst, LPSTR lpszCmdLine, int nCmdShow)
{
    WNDCLASSEX Window1 =
    {
        sizeof(WNDCLASSEX),
        CS_HREDRAW | CS_VREDRAW,
        WndProc1,
        0,
        0,
        hInst,
        LoadIcon(hInst,MAKEINTRESOURCE(IDI_APPLICATION)),
        LoadCursor(NULL, IDC_ARROW),
        (HBRUSH)(COLOR_WINDOW+1),
        NULL,
        ClassName,
        LoadIcon(Window1.hInstance, MAKEINTRESOURCE(IDI_APPLICATION))
        
    };
    if (!RegisterClassEx(&Window1))
    {
        return 1;
    }
    HWND hwnd = CreateWindow(ClassName, WindowName, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 500, 500, NULL,NULL, hInst, NULL);
    if (!hwnd)
    {
        return 2;
    }
    ShowWindow(hwnd, SW_NORMAL);
    UpdateWindow(hwnd);
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0)!=0 )
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

#include <Windows.h>
const wchar_t *g_MainWindowName = L"Tab";
const wchar_t *g_MainWindowClass = L"TabMainWindow";
const wchar_t *g_ButtonName = L"Start";
const wchar_t *g_TextName = L"Result";
LRESULT CALLBACK WndProc(HWND hwnd, UINT Comand, WPARAM wParam, LPARAM lParam);
int WINAPI WinMain(HINSTANCE hInst, HINSTANCE phInst, LPSTR lpszCmdLine, int nCmdShow)
{
    WNDCLASSEX TabMainWindow =
    {
        sizeof(WNDCLASSEX),
        CS_VREDRAW | CS_HREDRAW,
        WndProc,
        NULL,
        NULL,
        hInst,
        LoadIcon(TabMainWindow.hInstance, IDI_APPLICATION),
        LoadCursor(TabMainWindow.hInstance, IDC_ARROW),
        (HBRUSH)(COLOR_WINDOW),
        NULL,
        g_MainWindowClass,
        LoadIcon(TabMainWindow.hInstance, MAKEINTRESOURCE(IDI_APPLICATION))
    };
    if (!RegisterClassEx(&TabMainWindow))
    {
        return 1;
    }
    HWND hwnd = CreateWindow(g_MainWindowClass, g_MainWindowClass, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 500, 500, NULL, NULL, hInst, NULL);
    if (!hwnd)
    {
        return 2;
    }
    ShowWindow(hwnd, SW_NORMAL);
    UpdateWindow(hwnd);
    MSG msg;
    while (!GetMessage(&msg, hwnd, NULL, NULL))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}

HWND hwnd = CreateWindow(g_MainWindowClass, g_MainWindowClass, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 500, 500, NULL, NULL, hInst, NULL);

while (GetMessage(&msg, NULL, NULL, NULL)!=0)
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

HWND hwnd = CreateWindow(g_MainWindowClass, g_MainWindowClass, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 500, 500, NULL, NULL, hInst, NULL);