Volcano Heatsink Fan Is So Louddddd!

We have 2 computers in the household. The computer that i am in right now the heatsink fan is pretty loud. Comparing to the other computer in my sister's room it is quiet and smooth. But this baby is starting to annoy me. I want to leave my computer idle at night but noooo the fan is too loud and i cannot sleep. I know its a Volcano but i dont know which one. I remember long time ago it came with a switch for the fan but small as it is.. i think i lost it. So is there any way where i can create this fan to be silent??


Thanks everyone.