Дескриптор окна

[Crusher]

Можно и так:

....
ZeroMemory(&wc, sizeof(wc));
wc.hbrBackground = (HBRUSH)(6);
wc.lpfnWndProc = WndProc;
wc.lpszClassName = "Class";
wc.style = CS_HREDRAW | CS_VREDRAW;

wc.hInstance = GetModuleHandle(null);
....