Several keys on skyDX's keyboard stopped functioning. He asked the Desktops forum for help.
If your flute comes out lute, your pluck merely luck, and your bonanza a banana, try cleaning your keyboard. That might not fix the problem, but it's the best place to start.
Shut down the PC. Turn the keyboard upside-down (if you have a laptop, keep it open and turn the whole thing upside-down) and gently tap on the back so that crumbs and dirt fall out. Then use a can of compressed air (you can buy this at any computer store for a few dollars) to blow out whatever is still stuck. Be sure to read the instructions on the can, first. Then turn the PC upside-down and tap it gently again to get the last bits out.
If you have a desktop, you might consider unbending the end of a paperclip, and using that to fish out the junk below the keys. There's an element of risk in doing this--it could damage the keyboard (although it hasn't yet for me). That's why I strongly recommend against this for laptops, where a broken keyboard is a much more serious problem.
If that doesn't work, you need to figure out if the problem is with your keyboard, your computer, or your operating system. (It's almost certainly the keyboard, but it's worth a try.) First, try another keyboard. If you don't own one, borrow one. If you have a laptop, you can still plug in a USB keyboard. (In fact, I'm typing this on an external keyboard plugged into my laptop; I prefer it for ergonomic reasons.)
If the borrowed keyboard works fine (and it almost certainly will), you'll need to replace the old one.
This is cheap and easy if you have a desktop. I've seen USB keyboards selling for as little as $15, although if your concerned about ergonomics, you may want to pay more. Go to a local store and try out various models until you find one you like.
Installing the keyboard is a simple matter of turning off the PC, unplugging the old keyboard, plugging in the new one, and booting the PC.
Things get uglier with a laptop. You have four options here, none of which are ideal:
1) You can go the official route and have it repaired by the manufacturer or a manufacturer-licensed shop. This is the safest choice--your chances of it not working are minimal. But unless your laptop is still under warranty, it could cost a fortune. I've seen prices as high as $400.
2) Use a local repair expert that isn't licensed by your manufacturer. This can cost much less--$75-$100 in the estimate of one repairman I know. But you need to find someone you can trust.
3) Do it yourself. Repairing a laptop may seem scary, but people--and not just professionals--do it successfully. See Rick Broida's instructions.
4) Buy an external keyboard, plug it in, and accept that you now have a small, light-weight desktop.
For additional views, read the original forum discussion.