That's not the best advice Kevin
I have no problems with my anti virus, Nortons. It's your right not to use it but the problem comes if you have a virus and you're not aware of it and pass it on to others.
Anyhow, the question, i doubt there's very much you can do with XP to make Maya run any quicker. It's really mostly hardware related. You can make XP a little quicker, more responsive but the improvement in Maya would be minimal. You can have your swap file on it's own dedicated hard drive, it may help a little. It does with photoshop and is actually recommended i think by Adobe. In XP i use the classic interface as well as opposed to XP's overloaded one.