When I press the "Window" key (beside the ctrl) at the left side of keyboard, it shutdown directly. The right one "windows" key, it's normal as well.
The second problem is pressing "ctrl" will mute/unmute.
these seem like some additional function of some software.but you said that it come out suddenly.
I have used several keyboards,and now it's the 4th one.
The former ones come up with the problem much like yours when it's about to go bad.
I always use the CTRL regularly,CTRL+C,CTRL+x,CTRL+v,CTRL+s,CTRL+h,CTRL+f,CTRL+w,CTRL+q,CTRL+a,CTRL+1 .....
one of my broken keyboard comes up with problem before its deadth that : when I press CTRL key the start "menu popup", and when press WIN key the "task manager" show up.the "CTRL+" combines doesn't work any more.
the most important is I repaired it myself,although it does not work fine so long.
I remove screw nails with the screwdriver,open the keyboard cover,
there is a plastic flat(I googled but got nothing) in it , on the flat ,you can see many lines and points.
the flat sheet has 3 layers ,I found the lines next to each other a bit rusty and the lines somewhat crossed ,
then I use a eraser the erase the rusty out. and the keyboard work fine then,didn't work fine so long ,about couples of weeks.I spend a whole day to repair it
at last ,there is two choices for you:
- repair it yourself a whole day ,and not sure if it will be OK
- buy a new one
good luck!
wow after I post it ,I found so long this post is.