scanreg/restore in windows xp

stealer,
If  your XP doesn't boot at all, why not download the XP boot disk as referenced above, use it to boot your XP, then do whatever you wish with system restore ?
If XP had DOS you could run 'restore' from DOS, but XP won't have dos unless you patch it in someway.
The link above will give you a XP bootable disk, once booted use the command line for system restore.