Windows 9x and Windows 2000 internally cache DirectDraw DC handles. This guarantees that the same DC would be returned for ...

Windows 9x and Windows 2000 internally cache DirectDraw DC handles. This guarantees that the same DC would be returned for a particular surface regardless of how many times it was released and acquired. This compatibility fix aliases DCs returned by DirectDraw and then de-aliases them when GDI functions are called.