I cleaned my whole system. For the monitor, which is your classic kind, I just cleaned it like you would do for a tv. For the computer, I have a very soft brush which is adjustable so it can become stiffer if needed, and some q-tips for tight places and the fans, the handheld vaccum for getting the loose debri. I cleaned the case with cleaner while it was apart and away from the electronics.
Now for the keyboard. I completly dis-assembled it. I know these are not expensive so I thought well if it don't work when I get done I will get a new one. So I took it apart. Inside the first thing I saw was a plastic-like board with hundreds of white lines which react when you press the keys, sending a signal to a small electronic box, which goes to the cord that plugs into the computer. There are two of these plastic boards fitted together. I carefully laid these out of the way. Then I saw a bunch of little rubber type grommets which cover each key. Mental note 'remember which they are facing' as this is important. I dumped all them into a pile. Popped out all the keys and laid in order the way I took them off so could replace them exactly (forgetting I still had the box as reference) this made the casing very easy to clean. Back to the q-tips for tight spots. I cleaned it up good as new. This took a long time but I had set the time out of my schedule just for cleaning my pc. Just had to take some mental notes for reverse re-assembly. All back together.
I took Saran wrap to cover the keyboard, and got some dryer fabric softner sheets (two of these) to cover the backside of the pc. I had to think about this before the idea came to mind. I taped two sheets together in the middle, then taped the sheets to just the top of the back of the pc. This collects the dust better and keeps my fans cleaner. It also lets the air flow good. Still up and running good as new! Now I won't have to clean so often and I have a keyboard cover I can change, see through and does a really good job of water proofing and keeping debri out. No short cuts here.
Esk