WinXP has a built in backup system that will let you mirror your system for recovery.
Any hard drive that you purchase new to have a place to backup your hard drive will come with a CD with diagnostics and backup software, that will allow you to mirror the existing hard drive.
You can go to any hard drive maker's website (there are only a couple) and download an up to date setup program1 that well let you mirror your old hard drive onto a new clean one.
1 At Seagate, the backup program is a free trial copy that expires in 14 days, but you can download a fresh trial copy as many times as you want, or you can register the copy for a nominal fee if you expect to use it regularly (which isn't really likely).
A backup isn't significantly less likely to get corrupted or infected unless it's on a drive that is not connected to your system when you're not actually making or restoring a backup.