HELP! MY sony computer came with 2 harddrives and

My new sony computer came with 2 harddrives. One is 10 gigs and the other is 120, windows came installed on the 10 gig for reasons i am not sure of and bascially, when i do some really intense FLashing, it says i dont have enough memory. IS there a way to change your primary harddrive, either in Flash MX2004 or just in XP? Thanks