I have seen this a half dozen times.
Simple keyboard maintenace..
turn off computer and unplug keyboard from computer.
On the back of most keyboards is a couple of phillips head screws. Remove all of them.
This exposes the inside of keyboard. usually it's a film of some type clean this with windex. Many of these are plastic with a silver film on them if it's tarnished black anywhere clean with a pencil eraser. (note windex is an ammonia based product. Rubbing alcohol will do if windex is not available)
The upper half of keyboard usually has a bunch of little rubber bubbles to pop up keys wash these in regular dish soap and water.
Flip keyboard over take picture of key placement then remove all keys by poping them out from the back. Wash all of these with soap and water and an old toothbrush.
Keyboard base and top should also be washed same as keys.
The wire/cable that connect to a little circuit board with a microdot on it and leds leave it alone unless you spilled coffee on keyboard. If you did clean it down gently with rubbing alcohol.
Reassemble keyboard being careful to put the little wire balancers under the enter and space keys back into grooves of keyboard.
Total time to clean a keyboard is about 1 hour.
I usually do mine once every six months.
This will take care of:
Keys not working.
Computer beeping because keyboard malfunction.
Buying a new keyboard just because you dont clean yours seems a total waste as most people do not include travel costs to get said keyboard, which is usually $20, or more if you take public transportation.
although i have like 4 spare keyboards i have two that i have literally worn out some keys on. current keyboard actually has a groove in one key and the letters are missing althougher on more than a few keys.
although laptops are simular in problems they are much much more complicated to take apart.
Truthfully most laptops have a ports for external monitors, keyboards and mice. Unless you are on the road really you should be not using the laptop keyboard and touchpad. Use external keyboard mouse and monitor(dock station) when at home.
My personal preference is to have a tower system where there is components i can upgrade/ remove for warranty separate from main unit. Or can expand.
Just my two cents worth.
Next computer cleaning... use compressed air cans and a vacuum cleaner( put tin foil around hose and ground it by leaving a power cord plugged in but the power off (manual switch) on powersupply. If your power supply does not have a switch use a switchable power bar/surge bar with switch off. The ground is always connected.
Blow dust towards the vacuum but keep the hose on the edge of case never near any components or boards.
If you have fans use a pipe cleaner and brush down all blades on both sides. blow with air and vacuum.
Most video cards now have fans on them, usually more than one. Clean carefully with a plastic brush(cheap paintbrushes work good) blow with can of air and vacuum
The reason for vacuum(which is held away from components) is so you don't swallow the dust. It really doesn't taste all that good. If you too scared of vacuum just blowing the dust with the can of air is sufficient.