Whenever I boot it up, the USB optical mouse (hooked into the PS/2 port via adapter) and PS/2 keyboard both flash their lasers/leds, and then they turn off as normal. Then it throws a 8603 pointing device error and 301 keyboard error. Then 1 of 2 things happen: It goes to the bios setup with a dialog saying the same thing, or goes to the bootloader, then it says "System Security - Keyboard is locked" (note, there is keyhole on the back of the computer, not sure what it does though) and then near the end is a "176 System has been tampered with" followed by "Power OFF then ON again" followed by "The system is locked".
Note I cant use the keyboard or boot an OS (I tried a startup floppy to no avail). I've looked inside and saw nothing wrong, but when I saw a leaning diode I propped it back up.
Whats going on and how can I fix it?
(no, I'm not buying a new motherboard for this computer)

remove the CR2032 CMOS battery and put a screw driver or something between the 2 pads. Replace the battery and try turning on. This will clear the CMOS, and possibly remove the System Locked error and the tampering error, as that sounds to me like a BIOS password has been set.

But what about the mouse and keyboard error?

The keyhole prevents opening the PC (i had this on my long live 300GL)?

Fixed, but now throws out "161 Bad CMOS battery" and "178 Administrator password and boot settings cleared". I think the CMOS battery is fine (though I might of loosely reseated it though), and the worst thing that can happen is that I cant keep the time, and no administrator password is great and I'm pretty sure it will try to boot from other media if it can't boot from the HDD or something like that.