Hi I thought that you had already did a restore back to factory settings.
Did you just mean a system repair.
Factory settings is ok but it takes so long and probably with XP even longer.
I would leave it as a last resort and remember you will have to save anything that you need as factory Restore removes everything.
The restore is no problem it is just downloading all of the Microsoft updates and then adding all of your security programs etc back on.Give yourself about 4 hours as the updates are so slow and you have to keep rebooting to install them.