#include<windows.h>
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPreInstance,LPSTR lpCmdLine,int nCmdShow)
{
    WNDCLASS wndclass;
    HWND hwnd;
    MSG msg;

    ZeroMemory( &wndclass, sizeof(WNDCLASS) );
    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(NULL,IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL,IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = "windows窗口创建";

    if(!RegisterClass(&wndclass)) return FALSE;

    hwnd = CreateWindow("window窗口创建","window窗口创建",WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,NULL,NULL,hInstance,NULL);

    ShowWindow(hwnd,SW_SHOW);
    UpdateWindow(hwnd);

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

    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
    switch(message)
    {
    case WM_PAINT:
        HDC hdc;
        PAINTSTRUCT ps;
        hdc = BeginPaint(hwnd,&ps);
        TextOut(hdc,10,20,"哈哈，Windows编程创建的窗口！",28);
        EndPaint(hwnd,&ps);
        return 0;
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd,message,wParam,lParam);
}

hwnd = CreateWindow("window窗口创建","window窗口创建",WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,NULL,NULL,hInstance,NULL);

中的第一个参数是"windows窗口创建"!!!!!!

你直接写  wndclass.lpszClassName 比较好，免得打错。。。。

晕!