ive tryed both XP and Vista, now u can run most XP programs on Vista *some Required to use compatibility settings( Windows vista is better, than XP) Butt , Its new, so dont install it yet ,wait at least half of year, because ive i can tell you, you cant find any drivers for vista, u cant download files with other programs then IE, Its using very much computer requirements, plus half of games dont work... uve got my point