I was using a Windows Remote Desktop Connection to a Windows Server 2008 R2 terminal session on my Windows 7 PC and held the shift key down for more than eight seconds whilst I was thinking about what to type. This activated Filter Keys on the Windows 7 PC. I closed the Filter Keys panel without activating the feature and went back to the RDP session. I then discovered that the keyboard no longer worked in the RDP session. Disconnecting the session and reconnecting had no effect on the problem.
I have Googled and found no solution.
How do I re-enable the keyboard without having to reboot my logged in RDP session?