GP4 on Win 7 causes problems most time. Even if you would be able to start the game, it crashes very often during a race. People around here might say that GP4 runs fine on Win 7, but for me it doesn't. The only way for me to get GP4 working on my computer was with a Virtual Machine XP Mode. The game runs perfectly there without a black screen and without any crashes during the race. So if you want to follow this solution, just tell me in pm and I'll give you further instructions on how to install a XP Mode. If not it might be a longer and more difficult way to get GP4 working on your computer, I don't know. But I want to avoid that GP4 crashes during a race while you are driving.
Greetings, TGF1DRIVER