I have been having this problem for the past few weeks. I recently got a new computer in April, and its awesome. I have been having troubles lately though. I play lots of games including Battlefield 2142, Supreme Commander and Company Of Heroes. I just recently noticed that my pc isnt performing as well (Being Glitchy in games), and I checked the air coming out of my PC and it seems to be very hot. I dont see any dust though. My important specs:

-Intel C2D E6600 Water Cooled
-Nvidia Geforce 8800 GTX Stock Cooled

I dont know why its doing this, but some help would be nice.

There is nothing to worry about, the 8800GTX since it's very big would produce more heat then normal cards, download Speed Fan and give us a screenshot of the idle / after gameplay temps, if they are outragous ammounts ( like above 60c+ ) then you could try getting more fans.


Speed Fan Download:

http://www.almico.com/sfdownload.php

Yes, there is nothing to worry about, I play Battlefield 2142 on my laptop and every now and then i get a few glitches, and it gets VERY hot LOL
but it mainly depends on what is running in the background on your computer is you press the windows button and R on your keyboard (or go to RUN in your start menu) and type msconfig
You will then get a new window with some tabs at the top, click on the startup tab and uncheck programs that you do not want to run when your computer starts, if your not sure if you should turn something off then dont, but you can turn off things like Quicktime, Itunes, Microsoft Porgrams, anything like that, things you installed on the computer that you dont need on when you start it up, make sure you leave your antivirus turned on though LOL
hope this helps you