If you have corruption (spyware, viruses, etc.) I wouldn't recommend a clone. You'll just end up with all of the crap you were trying to get rid of in the first place.
What I would do is burn your data to a cd (doc's, photos, music, etc..). Burn your bookmarks, favorites from your browser, and burn your inbox folder from Outlook Express.
If you are satisfied with your backup, wipe the disk and then set the bios to boot from the cd. Put your WinXP disk in the drive, boot the machine. Create 2 partitions (most likely you'll end up with a C: and E: drive) Make your C: partition about 20 MB. Format NTFS and insatll windows. Load all of your programs and drivers, and run Windows update. Then as Baked says, get a copy of True Image and back up everything to the E: drive (or the Secure Zone). You'll have a bulletproof backup if things become corrupt....