iTunes for Windows is free, works natively with your iPod, and has support. There are others out there that provide different (though not frequently used) features, but you usually get NO support.
Now, FORMAT THAT HARD DRIVE, reinstall XP, and before you do anything else, INSTALL AN ANTIVIRUS PACKAGE. AND UPDATE THE THING RIGHT AWAY. Once you do that, and KEEP it updated, install iTunes (it works really well) and use it to manage your iPod. That's what it's for.
(Note: I've been a Windows user since 1985; you cannot take virus protection for granted on the Windows platform.)