After dusting my computer (not vacuum cleaner), and re-applying new thermal paste on EVGA GTX 660 SC, it gets overheated, while before it wasn't. Temperatures: before: idle - 40, max - 85-90, after: idle - 40, max - 100. What should I do?
The most common problem with thermal paste is applying too much.
What the paste is meant to do is minimize "stuff" between the CPU and the heatsink. This stuff can be air, or thermal paste.
Pastes like Artic Silver should be no more than a small pea in the center, then coated evenly. Other pads are measured for your socket and should be fool-proof.
Another possibility is that you should have used a good alcohol to clean the CPU and Heatsink before applying, otherwise you will not have a good contact between the CPU and HSF.