I found a completely different solution to this very same problem and my solution did not involve drivers,software or even hardware -- at least not hardware of the computer kind (you'll see what I mean by that in a moment). Anyway, when I'd depress my
left CTRL/C keys, instead of staying on the file I was trying to copy, the cursor would jump to another file and then just sit there. Same with CTRL/X. Since it had worked the day before and since none of the fixes above worked for me, I decided to do
a system restore. But that didn't solve the problem either. I was becoming more and more frustrated when I finally tried the CTRL key on the right side of my keypad. It worked fine for CTRL/C, CTRL/V and CTRL/X functions. Since the right CTRL key worked
and the left one did not, I deduced it had nothing to do with software, settings or drivers. I felt it had to do with a mechanical issue with the left CTRL key (which is the one I normally use). It was then that I noticed a shiny metallic object lodged
between the Fn key and the left CTRL key. So I pried up the CTRL key and guess what? I found a small nail (as in a wall nail) lodged between the FN key and the CTRL key. I managed to get it out using a pair of tweasers, after which the left CTRL key worked
fine. Luckily for me, the nail hadn't shorted out my entire keyboard! Just thought I'd throw this in just in case none of the fixes above work. My "fix" demonstrates how important it is to keep not only liquids, but small metallic objects, from falling
into your keyboard!