@ mikbro
I think the reason you keep getting warnings is that you have the warning system enabled in BIOS and it reads your slow-running fan as 'not running' as it can't sense fans running slowly. I had the same problem when I turned down the fan on my Zalman7000.
What worked for me was to disable the BIOS fan monitors and uninstalled Asus Probe. I did install and currently use Motherboard Monitor. I have a little window on my desktop that keeps me abreast of the fan speeds and temps at all times.
As for you, your problem is two-fold. One, you have the system monitor going and it can't sense your slow fan, so it sends a warning. Your second problem, and probably bigger, is that you shouldn't really be running a slower fan on a stock CPU HeatSink. The stock HSF needs to be going at the higher speeds to keep things cool. The stock unit is a compromise between cheap and efficient. If you really want to quiet the HSF, the best suggestion is to get a new HSF unit that is quieter and more efficient. You don't say what processor you have, but a little looking and I find you might have a P4 2.4GHz. Some of the better low-cost HSF include the Zalman7000 or the Arctic Cooling Freezer4. Pick up some Arctic Silver 5 thermal paste as well and you will have one 'cool' CPU and one less noisy component to worry about :sayyes: