Keyboard error - mixed buttons? Can't login or boot

[hayabus]

Hi! I have pretty much similar problem than described in this thread,
http://www.sevenforums.com/hardware-devices/269594-only-backspace-works-startup.html
except that I can't press F8 to open boot screen.
I only could get in the boot screen when I cold restarted, but my keyboard "don't recognize" any buttons, so windows will start normally to prompt a password.
I tried to use boot using my windows installation cd, but I can't "press any key to boot from cd/dvd..."

What could be causing this? I had another problem like this(none of the keys worked) before this, but I was able to log in using "visual keyboard-function". I re-installed drivers, solved problem.
Now I can't use visual keyboard at all

To add
-Both times, there was an security update (avast, malwarebytes) before the malfunction.
-I tried two keyboards, and several USB ports.

Is there anyway to boot my pc? Any help would be appreciated

 

[andrew129260]

You tried two different keyboards and none worked?

As well as multiple usb ports?

Does your computer have a ps2 connector, the non usb connection for keyboards? Maybe you could find a old ps2 keyboard if your ps has the connection and use that...

Tried resetting bios defaults?


Here is a whole guide if you do get the keyboard to work:

Please read this tutorial fully, and follow all steps.

99% of the time all issues can be resolved with problems starting windows with this tutorial.

http://www.sevenforums.com/tutorials/219533-troubleshooting-windows-7-failure-boot.html