Well, if you really want to lock your workstation, I think I have an old copy of OS/2 around here somewhere…
Just kidding-this guy sounds like a major jerk if he’s been repeatedly accessing your box without permission, and now reading this thread to find out what you’re doing as a countermeasure. When I worked at the State Department (in a secure area), any time we were going to be away from our desk for more than ten minutes we had to remove our hard drives and put them in a safe. These were fairly bog-standard machines, so the modification must exist. If ha><><0r dude is this skilled, this sounds like the only option, short of a biometric passcode, and that’s just silly.
What is the exact name/series and model # of your machine? If it is a clone what is the motherboard model #?
FWIW I don’t think your system has multiple BIOS passwords and I think your roommate has simply found a way into the machine by some hardware or related bypass and is playing with your head. I also find it vaguely surreal that someone who is breaking into your PC in violation of your direct orders not to do so is taunting you about this and living in the same house/apartment with you.
It’s not even that he’s that much of a hax0r. I’ll give him that he knows his way around a computer but try this: go to google and type “Award BIOS Default Password” You get like 4,300 hits. See why this is so easy for him?
MR BIOS is a replacement BIOS that has higher levels of security than most other BIOS’s. http://www.mrbios.com or 1-800-800-BIOS (2467) will give you technical details. They may have an inexpensive solution for your situation.