win注册失败

#include <windows.h>#pragma comment( lib,"winmm.lib")LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPervInstance,LPSTR lpCmdLine,int iCmdShow){ static TCHAR szAppName[] = TEXT("HelloWin"); HWND hwnd; MSG msg; WNDCLASS wndclass; wndclass.style = 0; wndclass.lpfnWndProc = WndProc; wndclass.cbClsExtra = 0; wndclass.cbClsExtra = 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 = szAppName; if ( ! RegisterClass(&wndclass)){ MessageBox(NULL,TEXT("This program reauires Windows NT!"),szAppName,MB_ICONERROR); return 0; } hwnd = CreateWindow(szAppName, TEXT("The Hello Program"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL); ShowWindow(hwnd,iCmdShow); UpdateWindow(hwnd); while ( GetMessage(&msg,NULL,0,0)){ TranslateMessage(&msg); DispatchMessage(&msg); } return (int)msg.wParam;}LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam){ HDC hdc; PAINTSTRUCT ps; RECT rect; switch(message){ case WM_CREATE: PlaySound(TEXT("hellowin.wav"),NULL,SND_FILENAME | SND_ASYNC); return 0; case WM_PAINT: hdc = BeginPaint(hwnd,&ps); GetClientRect(hwnd,&rect); DrawText(hdc,TEXT("Hello, Windows!!"),-1,&rect,DT_SINGLELINE | DT_CENTER | DT_VCENTER); EndPaint(hwnd,&ps); return 0; case WM_DESTROY: PostQuitMessage(0); return 0; } return DefWindowProc(hwnd,message,wParam,lParam);}边译ok,但在执行时,却出现了注册失败时所设定的字串"This program reauires Windows NT!"请问是哪边出了问题呢?????