My computer freezes up again and again

MY PC freezes without any reason. I have a processor pentium 4 2.2ghz. Ram 512mb and 256mb of Kingston. 40GB hard drive. Video card Ati Radeon 7000.

What happens is that I cleaned out all the dust particle from inside, but still the processor temperature is above 70 degrees so I think I will have to put new thermal paste into it so that it will cool down? Or is it the ram that is giving trouble. I am into differnet minds and cannot think of any possibilities to it. Please help me. Thanks alot

Yes you can try using the artic silver5 coolant and see if the problem persists.

See this guide: http://forums.techarena.in/guides-tutorials/1080461.htm