Here is a description of what has happened. I would like to have your ideas as to what the problem is.

Last night I shut down my PC using the normal routine. This morning, when I tried to turn the system on, it powered up, but would not go through the boot process. The system appears to hang before any drive is detected,before the system goes through the normal system memory check—even before the keyboard is detected. The only thing that happens is that the system correctly detects the processor types and characteristics. Due to the fact that the keyboard is not detected, I cannot even get into the system BIOS.
Could a virus have infected my system BIOS? Any ideas/suggestions are appreciated.