Don´t know if fan is the technical term to that thing whitch make a lot of noise :)
I heard some where that´s possible to decrease the power.
Anyone can help me??

sure, just connect the red wire of the fan to the yellow from the psu (should already be the case, one way or the other) and connect the black one from the fan to the red from the psu, it will run on 12-5=7 volts
or get one of those voltage regulators for them, either a rheobus, or a fanmate

Thanks *JW* !
I will trye to do that :)

this is a zalman model (costs about 6 bucks here in Holland)
you could go for a more fancy looking model ofcourse ;)
i've got thisone myself, the coolermaster aerogate 2
its got 4 temperature sensors and 4 connections for fans, fully adjustable and its got a blue led LCD and the button pannel has 7 colores, that can loop or just be set to 1 single color.
verry nice toy, the aerogate 1 has only 4 weels for 4 fans.

http://www.coolermaster.com.br/index.php?LT=english&Language_s=6&url_place=product&p_serial=ALD-V02&other_title=+ALD-V02+Aerogate%20II

my fan has 3 speeds...1(Low), 2(Med), 3(High)..I usually like it at 2..but when it gets hotter/colder I increase/decrease by pressing those buttons

:p