Some time ago I had trouble in my notebook. Some keys do not work properly. Incidentally when I menngunakan windows 7 operating system, I thought this was definitely a virus. That could happen because for this notebook does not have any anti virus installed.
I have some anti virus download, especially free. Then started the experiment, anti virus installed complete with latest updates. After that do a scan with a very saturate. The result is very disappointing, fixed knob is not working as usual.
There's crazy ideas, one of which troubled push button button simultaneously while annotate. And the result: Press right shift key and the left shift key simultaneously for a few seconds, then work
Hopefully this can help you to share your experiences problems.