I found three different ways for bypassing the password-check on a Toshiba-notebook. I had no chance to test them, so I can't promise they will work.
Hold down the left SHIFT-key upon bootup - this should skip the password-check on most notebooks and on some desktop-systems.
For this one, you will need an empty 3 1/2" disk (720KiB or 1.44MiB), another computer (to which you have full access) and a good Disk-Editor (e.g. Hex-Workshop).
This method should work on ALL Toshiba notebooks.
4B 45 59 00 00
This is a 25pin male connector which fits onto the printer port. You have to short-circuit the following pins:
After plugging the modified connector onto the notebook, the BIOS shouldn't ask for any password.