Q: GPU overheating I have an nVidia GTS250 that, in the last couple of months, has decided that it has a problem with newer games. Older games are fine, but anything made in the last couple of years will eventually make the system crash and apparently bluescreen (although I never actually see it). Googling the bluescreen code suggests it's an overheating issue; running a heat monitor reveals my CPU runs at a crisp 60ºC when idle but my GPU sits at 85ºC when idle. Turning on logging and opening up a recent game reveals the GPU temperature climbs to 115ºC while the CPU gets up to around 90ºC by the time it crashes.
I suspect I have two, intertwined issues - the GPU is just way too hot, and I've got airflow problems. (Sticking a housefan in there and taking off both sides of the case stops crashes, although the card still sits at 67ºC and goes up to around 100ºC.) Uninstalling and reinstalling drivers doesn't resolve the issue. Dusting with a can of compressed air didn't do the trick either (the temperatures I'm posting are post-dusting). The heatsink is right near an empty slot on the back of the computer. I'm at a loss as to what's causing the card's heat problems and whether it's fixable.
Some advice for resolving the airflow problems would be helpful as well. My case has four vents that could take fans, one in the front, two in the side (one positioned directly next to the CPU with a funnel attached, one underneath) and one in the back, but only the one in the back appears to have anywhere to screw a fan on.

A: WHOA WHOA WHOA!!! DO NOT DO THIS!
"use a vacuum cleaner to remove any dust form inside"
ARE YOU CRAZY? waaay too much static, might as well run a lightning rod into your motherboard...  go down to wallmart's electronic section and ask about a "can of air" follow the instructions on the can to dust your computer.
also a tip for your fans, use zip ties, they hold better than screws and you can put them anywhere.
but to your overheating problem i am having the same issue which is how i found this thread, i'm to the point where i think overheating just once has caused chronic problems, i'm going to rearrange the fans i have and add a third case fan and if that doesnt work i have an older gpu laying around that i'm going to install but for all my research this seems to be my only option.

A: So, if you think its a cooling problem, the best way to fix it is:

Turn off your PC, remove the power cable, use a vacuum cleaner to remove any dust form 
  inside. Post after you did this with the new temps. 
Take out the CPU cooler and reapply the thermal paste after you
  removed the old one. Use quality thermal paste. 
You can reapply the thermal paste on the GPU die also. That voids your
  warranty. So that's up to you.


A: It did indeed appear to be two intertwined issues: the lack of airflow caused the cooling on the graphics card I had to fail. I had to replace the card, and while I was at it I replaced the sole back fan with three smaller fans: two at the back blowing out, one at the front blowing in. (The principle here is that you're trying to create a vacuum that pulls air in your case out, with an assist from the front fan to pull cooler air in to replace it.) This happened to work for my case, which had superior attach points for the smaller fans.
Anyway, moral of the story is: if you don't have adequate cooling and airflow in your case, it's going to cause your components' inbuilt cooling to fail until eventually you just start getting crashes. Don't ignore airflow.
