I just upgraded to Windows 8.1. Since then I have noticed that Ctrl+C (copy) and Ctrl+V (paste) are no longer working. 
I have tried googling the problem, got frustrated and gave up. Help!!
Do they not work in MS Word or anywhere?
I don’t have Word. I am trying to C&P some text on a message board.
What browser are you using? Does this happen in all browsers? Does it happen in Word or another word processing program?
Have you tried shutting down and restarting Windows?
Try some simple cut and paste in WordPad or Notepad.
By the way…
…we understand completely. 
I am using IE 11. My laptop has been restarted several times. I have no word processing apps installed.
It was fine before I upgraded to Windows 8.1.
Maybe on your keyboard you need to use the other CTRL key.
I opened Wordpad and C&P worked fine. Then I tried it with text on this board, and it works!!! I could kiss you.
How did that fix it?
Oh, my. 
Who knows. It’s Windows. Windows 8. I suggested it just to isolate the problem but it sounds like you woke the right demon.
Thanks to all who tried to help. You guys are the best.
Mods, you can close this now. If you like.
Let us know if you have to C&P in WordPad every time you reboot your computer, to get it to work elsewhere.
Well, it seems the problem is solved, but I was going to say:
</Roy> 
Seriously. I was having a similar problem with copy and paste on my Windows 7 laptop a few weeks ago. (Maybe not quite the same as it only seemed to have a problem copying from Firefox, and it would occasionally work OK, but not most times.) A regular Cntrl-Shift-Esc reboot did not fix it, and I was contemplating appealing for help here, but, rather to my surprise, when I had to turn the computer completely off, for an unrelated reason, and then restarted it, the problem went away.