Its not Vista. ive got SH4 on XP and it comes up with the same runtime error as well. it also does it to the first Starwars battlefront game but not the second one. i have a hp intel core 2 duo processor with a ati radeon 9000 series vid card. so im just as confused as you are bro. any idea? oh somebody mentioned it might have to do with having a duel core processor.