XP should restore as you say but you will lose drivers for speacalist equipment as BB modem. if you have drivers on cd/ disk that came with equip then no prob, however if no CD/ disks then use device manager to show drivers then copy driver files to another partion or cd /floppy before doing restore.
Yes the Instant Support Tool will do this. However, you may not even need it. Once you have reformatted and re-installed all drivers your PC should have the same MAC address and BY should recognise it.