We surely often recommend cleaning the inside of the computer case to solve various problems.
I have to admit to being one of the helpers, who may get lazy about that important part of computer maintenance.
When I bought this Vista desktop year, and a half ago, the temperatures were pretty constant at about 19C-20C (while idle with maybe couple of windows open).
Then, pretty much recently those temps started to rise, and recently they were floating from upper 20s to even low 40s.
Finally, I opened the case today, and obviously there was a lot of dust inside.
Honestly, I was surprised how bad it was. I have a carpet, but the computer case is elevated couple of feet, so I really didn't expect that much.
Mostly fans, and around them.
Video card fan wasn't that bad, since it's pretty much open, but the CPU fan was really bad, and since it works in a box sitting on CPU heatsink, the heatsink was packed with dirt.
I cleaned everything well, and....as of now, with Firefox, and Thunderbird windows open, the temperature is listed as 14C-15C!
On average, 20 degrees cooler!
I'm pretty sure, my CPU feels pretty happy.
Spring cleaning time, people