sorry for lating about the answer.
at first the noise fan make me crazy also, becuase i work at night usually and home,
so im back to the company that had sold me the laptop, and i told them my problem,
and after suffering with them, they told me that some laptops usually have fan sound, and some laptops models have no fan sound 'silent' laptops, and you can
distinguish that by "Quiet Running" Logo at the model on the fujitsu website, the logo shape like a silent face,and the the company told me that i have 2 choices:
1- to see another model have 'quiet running' characteristic,and they will charge to me, or
2- return your money to you.
when i search the fujitsu web site, i found just 3 models, like lifebook E780,S710
the 'lifebook s710' is a nice laptop,but 14.1'' lcd, and becuase i want 15.5'' for my designing work, so i get the second choice, and after hardly work they return my money.
my email: firstname.lastname@example.org