Bdtyktl

The Ctrl, Shift and Alt keys on my laptop—an Acer Aspire 7736ZG laptop running Windows 7— have stopped working; both the left and right sets of keys. I have searched for solutions to this problem but I cannot find anything that works.

What can the problem be and what should I try to fix this?

Assuming that the problem is with software, try the following :

1. Fully patch Windows using Windows Update, including optional items (except Bing etc.)


2. Use sfc /scannow to verify system integrity


3. In Control Panel -> Device Manager, open Keyboards, delete your keyboard
   device and reboot (might need to use the power button)


4. In Control Panel -> Region and Language, in the
   Keyboards and Languages tab, click Change keyboards.. and verify that
   you are using the correct keyboard. (Have you got more than one?)


5. Boot into Safe mode and check whether the problem disappears.
   If it does, then an installed product is causing the problem.
   
   Use the System Configuration utility, General tab, click Selective startup and clear the Load startup items check box.
   On the Services tab, click the Hide all Microsoft services check box and click Disable all.
   OK out and restart the computer.
   
   If the problem still does not occur, turn on Services back in binary search mode
   until you find the guilty one.

Sometimes the keyboard gets stuck. I found that rapidly pressing the shift, alt, and ctl keys will eventually unwedge them. Try about 6 or 7 good presses on each in rapid succession, eg shift shift shift shift shift alt alt alt alt

This is often enough to wake the keyboard to the proper state.

You might find another symtom is that you can't click mouse-button 1, you always get the context menu following the mouse around. This is a cure for that issue too.

This sounds like an accessibility issue. I have XP in front of me only, but the answer should be similar for Win7. On XP, go to control panel and select accessibility options.

Under the Keyboard tab you have various options. On my PC, all of them are unchecked.

Stupid but simple: I connected a keyboard, in addition to the one already connected. As soon as Windows completed configuring the new keyboard for use, both keyboards were functioning properly.

My original keyboard now works well even though the additional keyboard has been disconnected.

I am not sure but I think it has something to do with the Human Interface Device Access Service. I tried restarting this service before trying the second keyboard, but it had not helped.

I had the same problem in virtualised Win7 under Virtualbox. The function keys Control, Alt, Shift (both sides) and Windows key stopped working for no apparent reason.

In my case the keys started working again, when I locked the Win, clicked on "Switch user" and inserted the same credentials of the already logged on user.

It's a bit of a voodoo, but none of the other solutions offered worked for me. (Except for the trick with connecting another keyboard, when I had the same problem some year ago, if I remember well...)

Open on-screen keyboard and when you type do the keys move visually move down on the on-screen keyboard or not? If no, get a new keyboard, its likely your keyboard has become very old. It happened to me. If yes, run ubuntu from a live disk and tell me if the problem still occurs
(NOTE: You DO NOT need to INSTALL Ubuntu)

I would change the Capslock to a control key using Autohotkey.

Capslock::Ctrl  

As for the other keys I would simple figure out what function keys you use least on your keyboard.