Because they ran vista on a low end trash pc expecting it to run.
A pc that has been bought lately (dualcore, decenty gpu and at least 2gigs ram) will run it flawlessy
It doesnt anymore, xp was thesame when they released it as nothing worked on it. Service pack 1 fixed alot of stuff and i can run any game now.
Dont forget to turn of the user account control though, it makes vista so much faster and less annoying.






