What happened to my computer?

Background: Here at school, it’s required that we log into a program called SmartEnforcer before we can access the network from the dorms. My PC is running Windows XP Home SP1… it’s a Compaq Presario. At the time I had 3 accounts on this computer, my admin account (password protected), a guest account and a limited account for my little brother.

A few weeks ago I was having trouble logging on through SmartEnforcer. I restarted the computer just to make sure it was the program and not my PC (which hadn’t been acting any differently). When I tried to log into my account, it lagged and wouldn’t respond. Nothing else was different about the startup process at all, it was completely normal. Eventually I was able to get in… at which point, the only folders in My Documents were the three “My…” ones. My desktop was different, and it looked like a random bunch of icons were strewn about on the desktop. Not the icons that were there when I bought it and not the way I had it set up by the time this all happened.

I tried one more time, restarting, logging in, and it was the same. I tried the Compaq Recovery. It said it’d restore all my data, but I guess at that point my data had been lost. It was all gone when Recovery was done. However… I went to install Winamp again, and my old Winamp skins were still on the PC. Also, when I installed a new font, all my old fonts showed up again. So some data is still there, right?

Also, I could access the network/Internet again, although SmartEnforcer was still not working. I continued to be able to access the Internet without SmartEnforcer for a few days before I got redirected to the install page when I opened my browser.

Most of my important stuff (photos, writing) was backed up elsewhere. It wasn’t that big a deal beyond the initial ‘aaaaack it all disappeared!’ moment. I emailed Compaq and got a reply that amounted to ‘uh, no idea. You had recovery disks right?’ So, I’m still curious about what happened. Any ideas?