Helping people with computers... one answer at a time.
Every so often a keyboard stops working or acts up. It's tempting to look everywhere but at the most likely culprit: the keyboard itself.
The number '2' key stopped working. And when I type the 'Q' key, I sometimes get a 'a' instead. What am I doing wrong? Is there a setting I need to adjust?
It's a surprisingly common question - a key on the keyboard is acting up for some reason. There are several reasons that a key might not work, but a very large number of people fail to realize a very simple fact:
Keyboards can break.
When you think about it, your keyboard is perhaps the most exposed and abused piece of equipment related to your computer. It's full of many, many moving parts, and - whether you like to think about it or not - dirt. Lots of dirt. All sorts of "stuff" that falls between the keys and stays there.
Given that, and how we often abuse our keyboards (tell me you've never pounded on yours - I know I have!), it's actually amazing that they last as long as they do.
When they break, various things can start to happen. When an individual key stops working all together, it's fairly obvious. But when pressing one key results in multiple characters being "typed", or an entirely different character all together - physical problems with the keyboard are always suspect. A short in the wires beneath the keys can easily produce all sorts of wired behavior.
So... your keyboard starts acting up. What do you do?
I'd eliminate the "easy stuff" first - software can play a role in getting things confused.
If your problem is around the Shift, Alt and Ctrl keys, you might want to check this article: Help! My Shift key is stuck!. There's an accessibility feature than can be enabled by mistake that changes the behavior of these keys.
If almost all your keys are producing the wrong characters, check out What's Dvorak, and why did my keyboard layout suddenly change? There are alternate keyboard layouts, and if your computer was mistakenly configured to use one of them, things can get very confusing very quickly.
If your keyboard seems to be typing on its own, this article might have a clue: Why does my computer go nuts sometimes? Voice recognition might be enabled and turning what your computer "hears" into keystrokes.
So what if none of those help?
Your keyboard might have a problem, or it might just be broken.
One of the things I often do is gently clean the keyboard with a little compressed air. Turn it upside down, or tilted to one side, I try and blow some of the crud out from underneath the keys. It can get fairly disgusting to see what's been in there if you haven't done it for a while, but this can sometimes remove dirt that is interfering with a key's operation
If that doesn't help, I always recommend shutting down, and then swapping the keyboard with another - or in the case of a laptop, plugging in an external keyboard. Assuming your replacement keyboard works, you now know that the problem is actually with your old keyboard itself. Keyboards are so cheap these days that replacing it is often your best bet.
If the problem doesn't go away even when you use a different keyboard, then it's fairly certain that it's your computer somehow. Unfortunately there are many places that could be a problem. The chances of any of them actually being "it" are pretty low, but at this point they're all you have left. They might include:
The keyboard interface on the motherboard
The USB interface for USB keyboards (often on the motherboard, or an add-in board
The computer's BIOS
The keyboard driver
anti-virus or anti-spyware software
conversely: viruses or spyware
Keyboard enhancement software, such as Intellipoint, keyboard macro tools, and the like
But in my experience the thing that most people overlook, that is in fact the most common cause of keyboard related problems is the keyboard itself.