Definitely, when you re-installed XP, it overwrote the MBR. Windows doesn't play well with the other kids on the block. You will have to boot from the deb install cd to get into LInux, or use Knoppix. Either way, go through the grub setup procedure as spelled out in "Zen and the Art of Using Grub", which is a good step-by-step for grub. You will have to edit either /etc/grub.conf or /boot/grub/menu.lst (whichever deb uses) to add XP to the grub menu, otherwise you won't be able to boot XP.
Search this board for dual boot questions. There is a great deal of discussion on the topic of Linux and XP.
Last edited by bigrigdriver; 10-02-2004 at 02:24 PM.