So I just installed a copy of GTA:VC (it may help you diagnose the problem if I tell you it's 'completely legitimate' and totally NOT downloaded from BitTorrent as 2 .iso files which were successfully installed and the original .exe replaced with a modified version so it would work, if you catch my drift).
http://forums.anandtech.com/messageview...atid=33&threadid=1821142&enterthread=y