Actually, I think your factory install cd would include recovery console, which can fix the mbr. Well, at least mine (SONY) does include it.
Secondly, since you have installed linux while also having xp, then, you would have another partition that you can install a new xp installation on while being able to access the ntfs partition.
I hope I helped.
you are correct in saying use the recovery console to fix the mbr. I have had to do this, and it saved me a huge headache of having to backup and restore my OS.
the command would be... I think..
Just a quick note...
I saw that you posted to a thread that is more than 6 months old. I don't think that that person needs help any longer.
I had problems similar to that (messing up boot loader) I just put in a win98 disk (i run win2K) and did fdisk/mbr this got rid of lilo (and grub once) and put the boot back to my regular win2K boot.
This thread has nothing to do with forensics. Just thought I'd bitch a l'il :)