just got FO3 and New Vegas via Steam, both games after installing have crashed to desktop with no error messages whatsoever, just completely crashed. in both instances of crashing i have been able to play the game for a little while beforehand, namely the starting areas and then just outside the start areas before game crashes. i have searched various fixes for this and have not had anything come up that works. minor changes to the .ini files, dxdiag, and most recently i have done a file verification on both games (have yet to see if that has fixed anything or not)

i'm running windows XP 32bit, 4GB installed ram(3.5GB useable), i5 650 3.2GHz, GeForce GTX 550Ti graphics card. the auto detect settings put it straight to ultra high.

any help will be greatly appreciated