What should you do when your PS/2 and USB keyboards aren't working at boot time?

Every computer needs a keyboard at the moment of boot time. Whether you are just bypassing BIOS or entering BIOS Setup, you need a keyboard to enter or change the value of the SETUP. In this case, no matter how skilled you are, you can't do anything without a keyboard.

This post idea came from the situation when I tried to build up a desktop PC with MSI mainboard, given by my cousin. He gave me the old Pentium 4 mainboard, and also given me the RAM and VGA cards. So after building it, I found that the keyboard just won't work. I tried with PS/2 and USB keyboard, and it just won't work. Then I called a technician who gave a solution which probably worked.

The solution is: turn off the PC and then remove the CMOS battery. Wait for quite a while around 30 minutes, then installed the battery again and turn on the PC. He said that this usually works well.

But unfortunately, it still didn't work for me. I brought it to another technician who was said to be expert in fixing mainboard.