A friend of mine wanted me to back up her pc hard drives onto my pc, then format her pc and install xp. i took the hard drives out of my friend's pc, put them in mine, and copied the files to my hard drive. not thinking afterwards, i right clicked on the other two hard drives that i backed up and formatted them while they were still on my pc. I re-installed them into my friend's pc and tried to boot to disk to install xp, but there's an error saying that the bootmgr is missing. How can i fix this so i can install xp on one of the hard drives?