the cooler is very noisy when Windows

Hello!
Actually started literally a week ago: when I boot Windows, starts to accelerate and the noise of the cooler, by all indications, is the CPU ( cooler master geminII sf524 ). The noise is like when you're playing, I mean that I load percents, but Aida shows the CPU 32C,that is norms,and the BIOS 47-50C. Also in the BIOS it enabled smart fan mode - the removal of this feature came up with nothing. Situevina this may not occur for two days, and then again starts making noise (by the way, the speed when the noise and no noise when - same) when booting Windows, the BIOS pauses. Every six months clean the system unit from dust, thought it the root of all evil, but it seems not.
Can someone push the idea into what could be the problem? Some process? Or the cooler is deteriorated (he was 6 years old, after all)?