I have Vista and it works good for the most part, not sure if i had installed the SP1 or not but I havent had any major issues, the only thing was i had to replace the sound card within the first few months because it stopped working. The only thing i dont like about it is when the user account control is on, all those security pop ups get old, so i turned it off. I used to have XP, but it was a dell and it crashed like 5 times befor i totally gave up on it. Plus i needed more memory so I went ahead and got the 4GB Gateway FX. Well worth the money, plus the screen is bigger than my tv...lol