No keys seems to work except f1 and f2. im on win7 64bit. anyone knows whats the problem?

also...everytime i load the game with loader.exe or normally i get black screen, and game gives a popup.
DIERR_UNSUPPORTED
MouseInit() : SetCooperativeLevel()
All i can press is OK. after that the dialogs starts.

Try using a 32 bit based O/S?
Good to hear it was Antivirus app. Enjoy the game!

no, my pc is with 64bit processor.But i now use different antivirus and reinstalled game.Game works perfectly well.

Do you use TrendMicro? I had the exact same problem as you, it turned out that my firewall was blocking OC3.EXE every time I started it. So you might want to check out your one. I use Vista 32-bit.
EDIT: Whoops, I wrote this message hours ago but I had no internet connection then. Seems like you solved the problem in the meantime. Have fun :)

well maybe this post will help others gets this rare error :)