I use Diskeeper to defrag both my hdd one is 40 gig the other 160 gig and i can do them both at the same time takes about 1/2 minutes to do both and less than a minute to do them seperate but i have the set and forget option enabled so its always defraging,and as said it gets quicker the more you do it.
You`ve got Windows XP. Start >All programmes> Accessories>System tools> Disc Cleanup and run it. When it ends its search click on OK. That should clear a lot of rubbish from your computer. You may or may not want to Defragment. Go the same route and you`ll find Defrag just after Disc Cleanup and you then are given the option to defrag as necessary. Result is a happy Esso43 and a quicker PC