I did some more thorough cleaning last weekend of the K6-2 system I wrote about in the previous post, and it appeared to have no cooling paste applied. There was a price sticker on the cpu though.
Now I know what the heat issues I frequently had came from when it was still my one-and-only pc. Now I don't use it anymore for doing school assignments, it finally seems to run fine and without reboots that used to come every 60-90 minutes. Solutions can be soooo simple, you only need to know them!