I just formatted my Sony Vaio S12X9E notebook and put Windows 7 Ultimate x64 on it. I went about the same way as I did last time (when it worked): I went to the Sony-page and downloaded and installed all of the drivers and utilities that came with the notebook. It's not working though.

Everything's working, except for the fact I can't seem to adjust the screen brightness: not with the hotkeys, not with Windows Mobility Center. As soon as I see the loginscreen of Windows 7, the screen is dimmed and I can't make it more bright. The first time Windows Update installed the graphics driver, there were about 5 seconds in the login screen that the screen was bright, after that the screen went dim. So I'm guessing it has something to do with the graphics driver of Intel (Intel HD Graphics Driver). It's the most recent though and I've tried a couple of older versions as well: no luck.

I also tried installing all Sony utilities. I guessed it could have something to do with the auto-brightness. When I turn it off, nothing happens though. Adjusting the brightness still doesn't change anything.

So that's basically what I tried. I'm all out of ideas at the moment. That's why I thought of asking here. I seriously hope you guys can help me, because I love my Vaio notebook for the rest.