Vaio VPCs13a7e and LCD brightness

[or4n9380x]

I have a Sony Vaio VPCs13a7e.
I changed hard disk, and reinstalled Windows 7 64 bit from a DVD, but now I'm not able to increase brightness of LCD.
The LCD brightness is the lowest, even if I installed Intel Graphic Driver and set it as maximum.
When I boot the laptop, I get an higher brighness for a while...when Windows 7 is ready to be used, the brightness becomes very low.
I did not install any Vaio's suggested program from Vaio VPCS13a7e web site.
How can I increase brightness?
Thank you

 

[MatildaPersson]

You might have it on a power saving mode. Try changing it.

 

[noidea_77]

Install the drivers for the function keys from sony website.

 

[or4n9380x]

I've already check it, I'm not on power save.
I set Full Brightness and maximum performance.
I suppose some features or utility are missing, but I'm not able to find which one.