Has the noise always been that loud,or did it just start???I guess it really doesn't matter as far as making it quiet,because I'd say your only option would be to replace it with a ball bearing fan.They tend to be much more durable and quiet,because of reduced friction.If the noise just started out of nowhere it's likely your fan's done for and I'd recommend replacing it as soon as possible,and not running your laptop for long periods of time(if at all) until you do.Overheating will kill your comp quickly and it's a b!tch to fix,because you don't know what's fried and what's not.It can be a frusterating and expensive problem.