Laptop Screwop

I have a friend that has a laptop with windows XP installed . I told him that I think this program is too big for his laptop . His computer seems to take forever to load start . Then all kinds of things are running in the background when he is trying to use it . Does he have the right program and if he does how can he stop some of these extra programs from slowing his computer down ? He only has about 450,000k of free space and has used 2.5 G .