Fan loud after latest Windows 10 update

[PeteFormerGeek]

My case fan has become periodically VERY loud since the July, 2017 general update to Windows 10. Never happened before the update and started immediately upon the update.  It seems to be CPU-load dependent: more-demanding applications (like games) cause the fan to go to hyper-speed for minutes at a time, then finally calm down again. Cycles high and normal.

[mdklassen]

Measure, measure, measure.

Google-search for "download free SPECCY".

Download/install/run SPECCY.

It will show:

* CPU temperature;

* motherboard temperature;

* disk-drive temperature;

* speed of CPU fan;

* percentage-busy of the processor;

Run it when the fan is quiet.  Run it again, when the fan is noisy. Compare the results.

Your motherboard is sensing the temperature of the CPU & motherboard, and when the values are too "warm", it speeds-up the fan, to try to cool things.  Faster spinning fans generate more noise than slower spinning fans.

What generates heat, you may ask?  As you have noticed, when the CPU is "working hard", it heats up. Same for your disk-drive, and your add-in video-card.

How old is the computer?

When is the last time that turned the computer off, and opened the case, and used part of a can of compressed air to give it a "blow-job", to remove most of the accumulated dust.  Dust is an enemy. (Yes, I just watched a 2016 episode of "Dr. Who", when the Doctor & Clara arrived at a space-station orbiting Neptune, and encountered dust monsters. The dust came from the corners of the eyes of the space-station's occupants, as they slept.)

[Big_Dave]

@PeteFormerGeek

Yes dust could be a problem.  You might also want to review this information.

[PeteFormerGeek]

OK. I just hadn't found a real solution to the problem - and, as I suspected, it was a problem with the Windows 10 update because as of the Windows 10 update of about Sept 10, 2017, the problem has stopped as suddenly as it started.   So... point being: it wasn't dust or excess heat: it was a problem in the drivers of the July, 2017 general update.

Nice to have a quiet system again.