How come this only works in Windows nt/2000?

I have this simple example taken from the Windows programming book form Pretzold:

Code:

#include <windows.h>

// Windows procedure function prototype - deals with
// messages
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hINstance, HINSTANCE hPrevInstance,
				   LPSTR szCmdLine, int iCmdShow)
{
	static TCHAR szAppName[] = TEXT("HelloWin");
	HWND hwnd;			// handle to the main window
	MSG msg;			// messages received
	WNDCLASS wndclass;	// main window class

	wndclass.style = CS_HREDRAW | CS_LREDRAW;
	wndclass.lpfnWndProc = WndProc;
	wndclass.cbClsExtra = 0;
	wndclass.cbWndExtra = 0;
	wndclass.hInstance = hInstance;
	wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
	wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
	wndclass.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
	wndclass.lpszMenuName = NULL;
	wndclass.lpszClassName = szAppName;

	// Register new window class
	if(!RegisterClass(&wndclass) {
		MessageBox(NULL, TEXT("This program requires Windows NT"), szAppName,
			MB_ICONERROR);
		return 0;
	}

	// Create new window (handle)
	hwnd = CreateWindow(szAppName,		// window class name
		TEXT("Window"),					// window title
		WS_OVERLAPPEDWINDOW,			// window style
		CW_USEDEFAULT,					// initial x position
		CW_USEDEFAULT,					// initial y position
		CW_USEDEFAULT,					// initial x size
		CW_USEDEFAULT,					// initial y size
		NULL,							// parent window handle
		NULL,							// window menu handle
		hInstance,						// program instance handle
		NULL);							// creation parameters
	
	// Window is now created. Show it
	ShowWindow(hwnd, iCmdShow);
	
	// Update
	UpdateWindow(hwnd);

	// Message loop
	while(GetMessage(&msg, NULL, 0, 0) {
		TranslateMessage(&msg);
		DispatchMessage(&msg);		// dispatches to WinProc function
	}

	return msg.wParam;				// return 0
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	HDC hdc;			// device context
	PAINTSTRUCT pt;
	RECT rect;

	// select an aption accoding to the message received
	switch(message) {
	case WM_CREATE:
		PlaySound(TEXT("hello.wav"), NULL, SND_FILENAME | SND_ASYNC);
		return 0;
	case WM_PAINT:
		hdc = BeginPaint(hwnd, &pt);
		GetClientRect(hwnd, &rect);

		DrawText(hdc, TEXT("Hello Windows"), -1, &rect, DT_SINGLELINE |
			DT_CENTER | DT_VCENTER);

		EndPaint(hwnd, &pt);
		return 0;
	case WM_DESTROY:
		// PostQuitMessage return 0 which makes the message loop end
		PostQuitMessage(0);
		return 0;
	}
	// windows automatically deals with messages that for some
	// reason were not interpreted by the program
	return DefWindowProc(wnd, msg, wParam, lParam);
}

How come this only works under Windows NT and not Windows 98?
Thanks.

Because you have a lot of typos. Have you tried to compile this code?

The only way that the code would not compile and run under WinNT/2000/xp (assuming you have corrected the errors) is if you #define UNICODE prior to #include <windows.h>. You should also link with winmm.lib to use Playsound ( the windows multimedia library).

Read what Petzold has to say about UNICODE and you will understand why the code wouldn't run on win98 if UNICODE is defined.