Too much noise the cooler on the CPU.

Generally talk situation. I got the computer worked for about 5-7 months without cleaning the dust from the (Yes, here such here conditions were, and my PC config look in a profile). Accordingly, it is more and more noisy, and finally my patience ran out (because rustled very much even in idle) and I found time to clean the inside of the system unit from dust, grease thermal paste processor, and so on..In the month of November (10-wow about), I actually and for all. After that, the noise diminished times (!) 3-4. In exactly a month (and that was December, somewhere also 10th) it so happened that I needed to reset the battery in the BIOS, so I climbed back inside the system unit. But the computer I was still working quietly, smoothly, all this was to reset the battery. After I reset the battery, I restarted the computer..and I heard a noise! This loud noise..first I thought not so good that cemented one of wentylatorow/coolers - but they were all in place like a glove. In General promuchavshis not one hour, the noise could not get rid of. It was noisy cooler on the CPU. Now the question is: why is it (the cooler on the CPU) runs at maximum speed? After all, to reset the BIOS all was quiet and smoothly, all the games are not hindered. After zeroing the noise of the cooler was incredible, but still works consistently. I think either you have to grease thermal paste processor, or the problem may be due to depletion of the battery in the BIOS (what's cooler works at the maximum? Or maybe the problem lies elsewhere?

Please help fellow experts :)