When you installed 2k It would have taken over the MBR (Master Boot Record). MS Products really like to do that.... This is why on dualboot installs you should always install the MS products first and then the Non-MS (*nix or other) products after. I'd suggest you fdisk /mbr and install a bootloader of some sort. Reconfigure Lilo or use Grub or whatever you already had or find a third party one and install it. You can get boot disks for all your operating systems @ http://www.bootdisk.com if you don't already have them. You can just boot your Linux install and your XP install of the boot disks if you so desire, or you can set-up the bootloader over again.