lagg,
How to get into the BIOS will vary from board to board.
Do you see any prompts at the top or bottom of the screen when the settings first appear that says "press <Del> to eneter BIOS" or "Press <F2> to enter Setup" or ..."Settings"?
Anything of that nature?
Also, as Tony asked, tell us something about the computer - is it a custom build, is it a Dell, an HP, what is it? If a motherboard, then what's the manufacturer and/or model #... if it's an OEM (Dell, HP, etc), tell us the mfg name and the model # (should be on front of case/tower, generally).
Also, if you are 100% sure it's not responding to anything on your keyboard, can you try a different keyboard? And with that, verify that you are rebooting at each attempt, and not just seeing it sit there for a long time, and then try different buttons. You have to hit the Del, F2, whatever before the PC attempts to boot from hard drive, CD, etc.
--
"If to err is human, then I must be some kind of human!" -Me