The GetClassInfoEx function retrieves information about a window class, including the handle of the small icon associated with the window class. The GetClassInfo function does not retrieve the handle of the small icon.
BOOL GetClassInfoEx(
| HINSTANCE hinst, | // handle of application instance | 
| LPCTSTR lpszClass, | // address of class name string | 
| LPWNDCLASSEX lpwcx | // address of structure for class data | 
| ); | 
If the function finds a matching class and successfully copies the data, the return value is nonzero.
If the function does not find a matching class and successfully copy the data, the return value is zero. To get extended error information, call GetLastError.
GetClassLong, GetClassInfo, GetClassName, GetClassWord, GlobalAddAtom, RegisterClassEx