or use an old refridgerator, and use the appropriate components to build a cooling system in your pc... then if u have enough space inside your tower, it can double up as a mini bar
yep former IT Technician here, if its making a large buzzin then the bearings will have gone. If its the fan on top of your processor then replace it asap, u dont want it to fail and fry your computer. If its a case fan (just a fan blowing air in or out the case) then it aint t0o important, if its the powersupply, just buy a new one when it goes bang.
lol mines off overclockers.co.uk for 35 i think. my servers got the two original dell 550 redundant powersupplies still going strong.