random resets due to overheating?

Hi -

I have been experiencing random reboots most of which I notice when I am playing games, but the do seem to happen at other points in time. I have come to a few conclusions myself, but wanted to check with other people to see if they had any other suggestions. My main conclusion is that my CPU is overheating

Here's what i'm running:

Windows XP Home SP2
Intel Pentium D 820 2.8GHz
Intel Tappen D945GTP Motherboard (Micro-ATX)
NVIDIA GeForce 6600 LE (256 MB) Video Card
2044 MB System memory (DDR2-533 DDR2 SDRAM)
250GB Hitachi HD (SATA)
80GB WD HD (IDE)
NEC DVD-RW Drive
Creative Audigy 2 ZS Platinum

I have a CPU Fan (of course), a 120 mm Case Fan, and a 5.25" Bay fan. Right now, my CPU (according to Everest Home Edition) is running between 60-65C (idle) and 66-upper 80sC (full load). I'm guessing that this is the main problem. But more than that, I think I also have a problem in just trying to run something this good inside a Micro caseI have given thought to replacing my CPU fan, but I was just wondering if I could get any advice on other ways to solve my problem (like reapplying thermal gel, or something like that). BTW the CPU fan that is currently running in my system is : Thermaltake TR2 M13 For Intel Socket 775.

Thanks for any help.