I would actually get this now because it is just so cheap, will run anything and with the money you save you could perhaps get another stick of ram or a nice case etc. But find me a C2D that will compare with that for that money. EDIT: Sorry for the double post, I forgot I could just add to my previous one.
Well if you are going to use it for gaming, I would Get the core duo cpu. And get Vista, because pretty soon games will only be compatible for Vista. Or you could use xp and update later.
dude to tell you the truth windows XP will be fast but thats not what he is worrying about.
Its the games etc..
512 mb would be okay for a computer for just surfing the net etc..
btw: aeroplane computers are awesome