Okay. This post will probably be a little messy because I'm going to cut and paste parts of it from similar posts on other forums.

-I came home today and turned on my Macbook (with OSX 10.5). I have Bootcamp installed, but OSX has been my default partition from day one. When I left the room and came back, I found that my computer had booted up into XP without any prompt from me. Finding this strange, I did a hard reset and loaded it up again. I got a very quick error message/logo (too quick to see what it was) and then the computer began to boot into XP. As far as I can tell, my computer can't find my OSX partition. Even when I use the Boot Camp utility in XP to boot into OSX, the same thing happens.

-After that, I've booted from the Mac OSX Installation Disc, opened up the Disk Utility, found the Mac partition that I needed, and clicked on "Repair Disk." Here's what I got:

"Invalid node structure, volume check failed. ERROR: Filesystem verify or repair failed."

-When I started to repair, the stats at the bottom told me that I was repairing a 107 GB disk with 3.2 GB of free space, which were the stats that I had last time the computer worked. Now it's telling me that I'm working with a drive with 107 GB free space, which makes me assume that my drive got erased.

I don't know what to do.