when i try to install nfs carbon it says that i need directx 0 or higher and i have installed the directx that is supplied with game itself but no diffrence.and i even updated my graphic driver(nvidia) to latest driver(93.71).any idea what the problem is?

I've got the same problem. Funny, it works under Vista build 5728

OK i found a solution for those who have the same problem.
just right click on autorun file on dvd and choose run in win2000 compatibility.then run the autorun.
ok i go play now XD

Thanks fatalwoomera!