Macs don't use a master boot record. Your drive has one, but it's only there so disk utilities don't see the drive as free space.
It simply sounds like he did an archive and install and forgot to update to 10.4.9. That would break Parallels, but reinstalling Parallels will fix it. It will also get rid of the Developer tools, but a reinstall will get those back. X11 should have survived.
Don't even consider reformatting or repartitioning. I don't think you have a problem with that. And there shouldn't be any reason to backup or mess with your bootcamp files either. You said in the first post that XP runs fine under bootcamp.
Overall, you may have to reinstall a few things, but it doesn't sound very bad to me.
Last edited: May 12, 2007