I have had something really weird happen today:
While typing, all of a sudden, almost each key of the keyboard was sending a tab after the key's own character, or deleting several characters or ...
For instance, I would type "a" and the screen would show "a ". Inside dialogs, any key would result in shifting focus to the next control (just as if I had pressed the tab key).
I tried an other keyboard layout, same problem. I checked to see if the tab key was somehow stuck. It wasn't.
I updated the virus definitions of Microsoft Essentials and ran a scan which returned clean. I rebooted the computer, and the problem remained. Eventually, I closed the lid of the laptop and took it over to the shop. And of course, as soon as I got there, everything was working perfectly fine.
As of right now, it seems to be working, but since I haven't done anything that should "logically" solve the problem, I assume it can happen again.
Any idea what the problem could be and how to solve it?
There have been no major changes to the system recently (except for the installation of a brand new USB 3G dongle from a reputable phone company, and everything worked fine afterwards).
I am running Windows 7 HP 64b.
Edit: The problem seems to be a hardware problem. I have tried booting in the Linux partition and the problem persists.
I plugged in an external keyboard which seems to work fine so the problem definitely looks like a hardware issue.