What happened to my XP User Account?

OK so my computer completely froze up on me earlier, and I had to manually power-down by holding the power button for 10 seconds or however long it actually is that you have to hold it to force it to shut off. When I rebooted, it came up with the normal user selection screen. I immediately noticed something odd - while my brother’s account still said that his account had 20some-odd unread messages, mine no longer said anything. I didn’t think to much of it, and logged in. It froze up again, and again I had to reboot. This time I managed to log in successfully, but it was clear something was amiss.

I ran virus check, just to be sure that wasn’t the issue, and it wasn’t.

All of my user settings were gone - wallpaper, shortcuts, the quick links on the start menu, everything. As if I were a brand-new user that hadn’t customized anything. All of my cookies were also gone, my favorites, etc. Luckily, all of my documents are still sitting safely in the Documents And Settings folder - but they aren’t accessible to me when I go to “My Documents” - just nothing listed there. So clearly some link between my log-on and its settings went poof in the night. The worst part was, I couldn’t re-save anything - settings didn’t “keep”, cookies just disappeared, etc. So I finally recreated a new user account, and can move over the relevant documents from the broken one, but I’m just wondering if anyone knows what happened, and if there’s an easy fix?