I tried the solution of Das33, but on my Acer Aspire 7739G the Bios is so useless, only few option allowed. I tried to update it on the offical Acer page here

http://www.acer.fr/ac/fr/FR/content/drivers

But it only make me move from my current V1.05 to v1.06, and it is a useless as the first one.

Here is the video that explain how update Bios, if it may give a clue to a final solution. I will keep reading here for help.

https://www.youtube.com/watch?v=lX0T07AzQw0