Problem adjusting brightness under Windows

[unrealiti]

Hi all,

I am new to iMac and new to here, hope I am posting into the right area.

So here's the problem:
I have bought a 21" iMac a few months back and installed Windows on it to run some Windows native softwares for work. Everything seems to work fine except the brightness adjustment is gone when running Windows. The brightness scale shows and moves when I press F1 & F2, but the actual brightness stays the same, at 100%, no matter how I change the brightness settings.

The iMac came with 10.7 Lion, which did not come with any form of install disc. Anyhow, I followed all the steps to set up Windows using bootcamp and installed all the Windows drivers from it. Everything was installed correctly as far as I can tell as Windows correctly recognizes the ATI 6770M on this machine.

Can anyone here please tell me how to get the brightness adjustment back under Windows? The screen on iMac is so bright that I literally cannot stare at it for more than 5 mins without getting my eyes hurt.

Here are the specs in case it's of any help:
21.5" iMac
2.7Ghz i5
4GB ram
ATI 6770M

Windows 7 SP1 32-bit

Many thanks in advance.

 

[31rhcp]

The brightness scale shows and moves when I press F1 & F2, but the actual brightness stays the same, at 100%, no matter how I change the brightness settings.

Have you tried fn (function) + F keys? If that doesn't work, try to poke around the Boot Camp control panel (click the little black diamond in the toolbar).

 

[unrealiti]

Yes the F keys changes the brightness scale the monitor itself doesn't actually change in brightness, it's locked at full brightness regardless of how I change the scale. I'm running BC 4.0 so the bightness control there is gone too.

Does anyone know what's wrong?

Thx.