Over the top fan???

[<~*Jay*Dub*~>]

For a few months now my desktop (emachines e4216, 3.0 GHz CPU, 2 Gb RAM, around 18 mths old) has been noisy - like a howling sound - It seems to be when I ask it to do most things - even scrolling a web page - and sometimes when its not obviously doing anything, Its doing it now as I read what I've written ! gently going faster then slower. Even when the machine is just turned on i.e. not even warm.
Its very bad when watching web video or playing music - too loud to enjoy the music. It did it slightly when new but not this loud, It could possibly date back to when I binned Vista and went to XP Pro, Interestingly I havent noticed it to be a problem when using Ubuntu, (I have it as a dual boot set-up on a seperate partition)
It seems to be from the CPU fan which has a plastic 'funnel' to draw air from (or to?) the outside of the casing. Do I need to install a grafix card, maybe that would help? Or maybe an adjustment of some kind. ...I feel myself reaching for the hammer
Be gentle with me I'm not too savvy
- John.

[mountain_rage]

You might have to blow out the air from your case. If there is too much dust in your heat sink it could screw up the cooling causing your fan to be spinning up higher to cool the system.

Its also possible your fans ball bearings are on the fritz, in which case you would want to replace the fan.

Other possibilities is that you have something running using up a lot of resources and making the fan spin up for cooling.

[1cooldude]

If you can isolate the noise source as the CPU fan then I would replace the fan.I know that you've already attempted (http://forums.techguy.org/hardware/840010-over-top-fan.html) to blow the dust off the heatsink without any improvement to the noise level.
Also, ensure that the shroud is properly mounted as any air leakage could very well contribute to an increase in noise level.
Not sure what type of a CPU fan you have but most OEM types are rather cheap quality and replacing it with an aftermarket type will probably improve your cooling (with lower noise level) and improve the operation of the CPU. Keep us updated. Cheers.:)

Q: Do you have a side case fan?

[Signa]

Most dieing fans sound like a lawnmower, and not just being over powered. I'm guessing the heatsink is clogged still, or some manual settings got tweaked to "high"