Well photoshop uses a hell of a lot of CPU power too so its not necessarily your graphics card ... and > 70 degrees C is a problem. Ok, the heatsink is the big metal thing with a fan that sits above your CPU too keep it cool. Thermal paste is available at nearly every PC store, and instructions on the packaging are pretty clear. If you ask a tech guy who works at the store they should be able to give pretty good advice (not so useful if you order over the net). http://sysopt.earthweb.com/paste.html That gives a fairly technical description of what thermal paste is. http://www.neoseeker.com/Hardware/faqs/kb/5,61.html Gives a fairly straight forward guide Obviously if you are really unsure then try another option as there is a possibillity of complications when re-applying the thermal paste.... A tempoury solution is to run the PC with an external fan...but thats not a very good long term idea.