I had some troubles with default icon also
. My solution is as follows and should work for anybody.
First make and icon and put it in resources.rc file like that:
Also make sure you have a define in your resource.h file:
(Value is totally up to you as long as it doesn't collide with some other icons )
Next in you main .cpp file in DarkGDK function before main loop, set it by using SendMessage like this:
SendMessage(g_pGlob->hWnd, WM_SETICON, ICON_BIG,(LPARAM) LoadIcon(GetModuleHandle(NULL), (LPCSTR)IDI_ICON ) );
I hope it'll help