My Tablet-PC kept overheating and crashing.  I found I could fix it temporarily by putting it in the refrigerator for a while. Finally, I used the vacuum cleaner to suck out all the dust from inside.  Watch out!  Don't use a big vacuum on the keys as they will get sucked up into the vacuum.

My Regular-PC was more of a challenge.  It too was crashing.  Putting it in the frig just made things worse.  I was tossing and turning in my sleep when George Costanza appeared in my dream.  He pointed his figure at me and said: “If everything you do is wrong, then the opposite must be right”.  It was at that moment that I realized that putting this second computer in the frig was a mistake. I immediately got up and headed downstairs to warm up the oven.  Once is was a bit hot, I placed my computer in the oven on the hot tray with the rubber feet pointing upwards so they wouldn't melt.  With the hot oven turned off, I left it in there for a couple of minutes.  When I took it out, it was quite hot, but it worked fine, and has worked great ever since.