I installed CoD4 on Windows 7 x64 RTM. And I tried to play multiplayer and it loads to a black screen, then the black screen gos away and it gives me a error saying it couldn't start. I googled this and I heard of problems with the punkbuster. But I didn't install it, and I didn't install it in the program files. I tried program files and it didn't work. Single player loaded, but gave me a line going thru my tv, going from top to bottom across it. But was fixed by adjusting resolution and aspect ratio. It's not my tv because I play many other games too.