Software Piracy is not condoned here, nor will anyone help you with pirated software problems.
I can think of two ways around that problem off the top of my head, but you have to figure out what they are. If you can't, or don't want to, buy a legal copy of XP. If your friend is willing, you can buy an additional license for his copy with a $10 discount off of retail prices from Microsoft.
I used my friends Windows XP professional edition on my computer, but I cant download any of the critical updates for the computer because this edition has already been registered to someone else, is there a program I can run to override this problem? Thanks!