Remove the CPU tunnel and reverse the rear case fan to blow out.
Add an 80 mm case fan on inside front of
case blowing in.
This should take care of the heat issue.
My cousin owns a Compaq Presario sr1707al. I just installed a nVidia GeForce 8400GS on his computer. He needs to keep the case open or the computer will BSOD. I've tried increasing fan speed and underclocking, but neither seems to work. Is the Graphics card defective? Have any of you had this problem? His OS Windows XP Professional SP2. All drivers are up to date.