Windows 7 X64 randomly stops recognizing the keyboard

Happend to me, some files are corrupted in the system.

Check out in your Device Manager and do a Property on your keyboard.
Go to Driver tab, and click on Details.

Verify if the drivers are certified by Windows, if not, you have to chance these files.
 
It has 2 drivers i8042prt.sys and kbdclass.sys and both are windows certified. I tried to update the driver, uninstall the keyboard and reinstall it. Did a system recover from 2 weeks back, updated the bios, and now I'm running out of ideas... any suggestions?