Microsoft recommends that you reinstall Windows every 6 months (due to file and registry corruption). It's a major inconvenience, but must be done --- which is one of the reasons I converted to Linux. However, you can make it a lot less painful by making a
slipstream copy of XP, assuming you have a full, non-OEM version and it's not XP Home Edition. That way, you can install all of the patches / updates in advance. When you reinstall, you've already got a pretty up to date system. Or, like B already mentioned, you can buy a copy of Norton Ghost and make an image of your HDD with all of your software already set up and configured. That way, when Windows does its thing and crashes hard, you can be back up and running within a half-hour. The problems with this solution are that:
a) You have to have a seperate HDD or large partition for your drive image(s)
b) When you restore the backup image, you'll still lose any changes made since the time of the image
c) In most configurations, HDD images are vulnerable to certain viruses. They can be corrupted and therefore unusable
d) Unless you have the image located on a file server with some drive redundancy, your backup image is still vulnerable to hardware failure
e) Norton Ghost is retail software and costs $20 (for a home license)
-AT