ironbeard

Hello all, Was wondering if anyone could tell me whats the biggest hardrive I can put in an old dell optiplex 260? has a 40gb in it, but my 11 year old uses it for city of heros, and wow, and apparently wow has come out with a patch, and now he cant play, so i went out and bought a 500 gb hardrive for it, but was wondering before I started fooling around with it to much if it would work or not? Would appreciate any info you could give! Thanks, Ironbeard