Don't even bother, you can't possibly hope to put XP over a wobbly un-stable operating system like ME, I've tried it before & found that after spending all day re-installing programs etc, then you could spend the next day trying to find out why you can't connect to the internet, your system starts falling over like an Italian striker in extra time!
You may as-well back everything up, re-boot, set the bios to "boot from cd" & let XP do it's thing! oh yeah, invest in a small hard drive, say 5-10 gig, then when it's all up & running, create a ghost image so next time any major dissaster happens, you'll be up & running in 10 minutes again........ ah, we all have 20\20 vision with hind sight!!!!