There are some registry edits that i found on the internet that will make your windows XP machine shut down faster. There are also some out there to boot up quicker, and just run better in general. Here are a few:
http://windowsxp.mvps.org/slowshutdown.htm
Doing these will help your computer shut down so much faster. I did it to mine, and now it shuts off in about 20 seconds. Its incredible. Its good for me because I use a laptop. If anyone finds anymore registry edits, post them here. I’ve got a couple more i’ve done, but can’t find them… If I find them I’ll post.