Other than the monitor, you will probably need to clean the keyboard more often than the rest of the PC. Dust and debris can collect between the keys can affect their functioning. The surface of the keyboard and keys can be wiped over with a cloth lightly dampened with warm non-soapy water. You must avoid getting the keyboard wet as it may cause damage to the keyboard circuits.
To give the keyboard a thorough clean or to do a close visual inspection of the keyboard, remove its cover. By removing the key caps of the - (minus), + (plus), and Enter keys in the numeric keypad at the far-right end of the keyboard, you can create a gap to remove the debris from the keyboard.
Small non-static vacuum cleaners can be used to remove debris from the keyboard as well as other small parts of the PC. These usually have a small brush head attached with a gooseneck that can be bent to provide the best angle for cleaning. Compressed-air can be used to dislodge debris from inaccessible parts of the keyboard. Dislodged debris can then be safely removed by vacuum. Large pieces of debris can be carefully removed using non-static brushes, tweezers or probes.
If the keyboard has had something spilled over it, you must act quickly to save the keyboard circuits from permanent damage. If a spill occurs over the keyboard of a laptop computer, the liquid may also penetrate through the keyboard to the case damaging other components of the computer. It is inexpensive to replace a keyboard but expensive to repair or replace a laptop.
In the event of a spill, immediately disconnect the keyboard from the computer, or disconnect the power from the laptop, and turn it upside down to prevent the liquid penetrating any further. Wipe or swab out all areas you can reach. A hairdryer can be used to dry hard-to-reach areas, or leaving the keyboard upside down to dry overnight may work. Ensure that the keyboard is completely dry before reconnecting it to the computer. Once you are satisfied that the keyboard is dry, reconnect and reboot the system, observing the POST for keyboard errors, and test the keyboard by pressing every key and verifying its action. If there is still malfunction of the keys, you may need to replace the keyboard.