so your Linux distro is installed in sda5 and it is the only linux drive you haev rite??

to boot 2 ubuntu, change root to root (hd0,4) and reboot...

Your XP's some files curreptd... to fix thz, boot from XP CD and go to recovery mode... then type sfc /scannow....

I hope it'll work...

Rock On!!
LiNuX RuLeZ

As I indicated in an earlier post, your windows installation in on a logical partition and you will need to install at least the boot files for xp on a primary partition. You have only one primary partition so you should be able to create another. Never used xp so have no idea how to go about this. Suggest you check microsoft support site or windows forums.