I can't log into Windows 8 because my keyboard no longer works. My Caps Lock key lights up and Windows recognizes it, but the ordinary abc keys are nonresponsive, preventing me from logging into my Microsoft account.
I would use the on-screen keyboard, but when I launch it, a pop-up appears for a half-second, then disappears: "On-Screen Keyboard Could not start On-Screen Keyboard."
Update: 50% of the time, when I reboot, I lost alphanumeric keyboard functionality AND on-screen keyboard functionality. The other 50% of the time, both work perfectly. So there must be a root cause for both.
MacBook Pro 2009