lenovo desktop win 7 prof the letters qwer stopped working.I rebooted -still same.I did System restore and it worked Next day ...same problem.Tried System restore but did not work.Placed in different USB- installing software - but hangs on latest updates , but keyboard started working. Next day ...same problem .This time after repeated USB disconnects it worked But i am getting fed up with problem Useless Device manger says it is working and my drivers are up to date
try the keyboard on another computer to see if still have a problem. could just buy another keyboard as $10 & up.
Flip it over and give it a few good slaps. Computers are like kids sometimes. It might just have some crumbs in its bum.