Bart Lagerweij has been providing the means to generate one of the best Boot discs and general repair tools for some time now for WinXP.
I tried this out with my Toshiba laptop with XP Home on it.
The instructions were easy to follow and accomplish.
Essentially, it boots up a minimal Windows environment from a bootable CD.
It is legal, because Bart's PE builder generated the Boot CD from your existing OS that you 'own'. Bart is not distributing an OS.
If you have 'hosed' your system, it's a great tool to get back into the computer.
As many computers come with instal 'images' rather than the retail type CD which can boot into a recovery mode, Bart's is an excellent recovery tool.
You can get the new version here:
http://www.nu2.nu/pebuilder/
BTW.......it's free!
Jack.