If you formated the drive the grub isn't there it is somewhere else. If it was truley formated there is nothing but 0000 0000 written all over that drive...

Did you completely format the disk or did you quick format before reinstalling xp? Once again if you reinstalled xp after a format 0000 0000

Do you have a cd? you can also manually install drivers with an exe by picking the driver you want out of that archive...I'm on vista right now and can't look up the process but I will get back to you tomorrow

and for nero...I would stay attend to problems 1 and 3 first