During setup, Windows NT 4.0 may stop responding or crash in Win32k.sys. 

CAUSE

A user mode callback occurs on the desktop system thread for a WM_SETICON message, causing the computer to stop responding. 

STATUS

Microsoft has confirmed this to be a problem in Microsoft Windows NT version 4.0. This problem was corrected in the latest Microsoft Windows NT 4.0 U.S. Service Pack
 

Note: WM_SETICON is a message which can be posted to any window to get it to change its icons and is very useful for dialogs and other situations where the class is registered out of your control. The following code segment will illustrate how to associate an icon to an application.

First make an iconresource with both an 16x16 4 color and a 32x32 4 color icon. Give the Icon an ID of 1.  WNDCLASS wc;  wc.hIcon = (HICON)LoadIcon(hInstance, MAKEINTRESOURCE(1));  SendMessage(hWnd,WM_SETICON, FALSE,(LPARAM)LoadImage(hInstance,  MAKEINTRESOURCE(1), IMAGE_ICON, 16, 16,  LR_DEFAULTCOLOR));  The above code assigns an icon to the window and sends a message to the taskbar to put icon next to the application name, because the default is a rather dull icon.