I have read all the tips re computer cleaning and they are very much what the Langalist used to recommend. (Sad that Fred sold out)

I did however pick up a "risky" tip and I HAVE used it very successfully.

MOST cleaning advice NEVER mentions the Power Supply. IF it does it says "leave it alone" and for very good reason. The components can retain lethal charges for quite some time after it is disconnected from the mains supply. HOW LONG? I know not.

BUT Power Supplies have FANS and, having significant electrical components. Power Supplies  DO collect "muck" (electrical attraction)  AND then run HOT which then affects everything else inside the case.
With MOST Power Supplies it is usually easy (and non -lethal) to remove the fan from the outside and give it a good clean. Sometimes even replace the fan.  But THAT is only part of the problem. There is still "muck" inside the Supply.
I very carefully removed the casing from MY supply and was amazed at just  how much "muck" was there. I could hardly SEE the components!

Removing the casing was NOT easy and I cannot advise. You will have to examine YOUR case and intelligently decide WHICH screws are the ones to remove.
THEN it would be a GOOD idea to don a pair of rubber gloves!!!

As I said I found much "muck" inside my PS (but then I'm a smoker and a VERY careless housekeeper!!!) It was clinging to ALL components and wires and BLOCKING the heatsink.
I used a very soft photographic lens brush to remove most of it and THEN used compressed air. When I'd finished it looked pristine. Re- assembled everything, ran the oomputer and lo and behold case temperatures had dropped by at least 5 degrees!!!
IT was actually EASY, if stressful. Just TAKE CARE if you try it.

Hello,
Well, I have done the completely undo the computer keyboard for cleaning and was very successful.... two things I can suggest.... a digital picture of the keyboard before you start.. this is so you don't have to rely on memory as to where the keys go, should they fall out...  I put mine in a dispan and washed them... I have been typing all my life but you would be surprise how automatic it come and when it comes to putting them back where they should be, how short minded one can be.... The other tip is I used isopropel alcohol and Q-tips for the cleaning of the hardwired part, or what some call the circuit board.
Good luck, Betty in Va.