|mmm... Let's go back a wee bit...|
Make/model of system under discussion?
Have you set the first boot option (in bios) to be CD/DVD?
Is the XP disk you have a retail or OEM full/Upgrade version; or is by chance a recovery disk?
As to your proposed path to wipe the drive etc...
Not having used Bart's disk not commenting from experience... But in theory yes it orta to work. But again ensure DC/DVD is first boot device (in bios).
As you acquired the box from a garage sale.. I'd be very inclined to rebuild it (as in wipe/re-install) regardless of how do it; rather than try to remove some items etc...Otherwise you have no real idea of what's on it etc... Better to rebuild it for whatever purpose you have in mind anon...
Also rather than install McAfee etc.. (which will cost ££/$$ anon) consider/install avast (avast.com) as it's free (for home use); and works without hogging resources etc. (unlike Norton - and as some suggest - as does McAfee ).