If you are going to do a fresh install (which I chose to do on my home computer 'cause nothing's more fun that a nice clean install!) I'd recommend looking into a program like Autostreamer downloadable at http://www.softpedia.com/public/cat/12/2/12-2-183.shtml
to slipstream your XP installation.
I had never heard of slipstreaming when this program was recommended to me and I used it and it worked flawlessly. To use it, you'll need your XP CD and the network version of SP2, which can be downloaded from Microsoft.
Whether or not you *should* do a fresh install it really up to you. I think you're much less likely to have problems with it if you do... but then again, if you do have problems, it would be much harder to "go back".
-my 2 cents.
Oops, forgot to add you'll need a CD burner so you can make a new XP install disk with SP2.