Assumption: You installed VL after XP and you use GRUB boot loader.
Go ahead and re-install XP to the same drive it is on now. It will take over the MBR and wipe out any "competition", but your files will be safe on the separate hard drive.
Then boot from the VL install CD, but use the "linux root=/dev/xdx ro" option (replace /dev/xdx with actual location of VL). Once logged in to VL as root, re-install GRUB to write the new multiboot MBR.