Mines a non smoking house but the dust that gets into my pc is incredible, i take it to bits whenever I feel the fan is coming on a lot , this normally indicates it is having trouble keeping a cool operating temperature, I take it outside and using the blow exhaust on my henry type cleaner blow all the rubbish out ,
I don't see the smoking link here at all, yes if you are a smoker then you will find that your cd rom drives won't last as long due to tar build up on the lens, but heatsinks and cooling fans... thats dust not tar!
this is probably not due to dirt,. it is the fan beaering or bushes worn out - change the fan.
this is likely the fan on the graphics card also possibly the cpu fan or case fan. in any case get it done sooner rather than later as it won't effectively cool your system and this can lead to more damage.
thanks for ur answers, the fan is turning ok and ive cleaned it with the vac , but its still making the noise, i dont know how to open the back of it theres that many screws
chuck
I think the smoking connection is that all smokers are dirty AND lazy so never clean anything ;-)
bantam
you can't haqve cleaned the correct fan if you haven't opened the box
looking at the back of the box (assuming a tower)
undo the 3 or 4 screws on the right hand back edge
and slide the side towards you https://www.youtube.com/watch?v=5FjToaUV5Tc
alternatively follow romko's advice and rebuild the whole machine
My pc usually purrs like a cat figure of speech lol but all of a sudden it started doing the same a loud reving noise, i knew it wasn't anything to do with the fan as it had been cleaned and had been working great, so i thought the only thing i can try is to give it a good clean up itself, so i did virus scan, spyware scan etc cleaned up cookies and did a defrag, then rebooted and it's back to it's normal noise.