Hi Larry,
Shuld I apply the Thermal Grease to the Heat Sink and CPU for my K6-2 500MHz? I upgraded to it from 350 on my EP-51MVP3E-M based system, at the same time beefed up the memoty to 384MB from 96MB and upgraded the 8MB AGPx2 to 32MB AGPx2. I also replaced the CPU fan with a small case fan... 
When I replace the left side cover on the case, (which is the 1/4 extra width kind you get when buing Alto systems) sometimes the alarm would come on for a while anyway. (this is happening pretty randomly - usually the temperature is no more than couple degrees above the alarm level)
If yes, where can I get and which one is a good quality Thermal Grease?Also, when I connect this new fan to the motherboards 3pin socket for the CPU FAN, it will never turn on.
If I connect it to the motherboards 3pin socket for the CHASSIS FAN it will always stay on. What may be the mater with the CPU FAN socket? (I tried it before with a 3 pin CPU FAN, with the same result, so I was using the 4 pin connection CPU FAN directly powered from the power suply)
Thanks a lot for your input, this is the best site of this kind I ever seen!