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I have no idea what's going on here, I hope someone can help.

Windows 7 x64 was installed and fully updated on an Intel Mac. It seemed to be working fine, but there was no sound, so I installed the Windows Bootcamp software from the OSX 10.6 DVD. It installed a ton of drivers, and now I have sound... yay, but the Apple Cinema HD Display brightness was set to minimum. Everything was too dark.

Now there doesn't appear to be any way to increase the brightness. The button on the monitor does nothing. There's no Windows option that I can see. The monitor driver is set to "Generic PnP Monitor", which sounds like it could be the problem.

I can boot back into OSX and change the brightness there, and it sticks until I log into Windows where it returns to the minimum brightness again (so it stays bright all through the booting of Windows).

It seems my only option is to uninstall the Apple Bootcamp software and lose the sound again.

Anyone got any ideas?

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Rather do a downvote driveby, how about explaining where my question needs improving? – Django Reinhardt Feb 6 '12 at 13:59
Is the problem happening when you're booted into the Apple OS or Windows or both? – music2myear Feb 6 '12 at 14:59
@music2myear Hi, thanks for your reply. I've updated my question with more detail. I can alter the brightness in OSX, but it changes back to minimum after I log into Windows (it's fine before then). So strange :( – Django Reinhardt Feb 6 '12 at 15:04
Got it, based on the updated question, it's a driver issue for sure. Windows simply doesn't yet have the drivers for the display brightness control. I see the answer below already correctly IDed the solution as well. – music2myear Feb 6 '12 at 16:08
@music2myear Yep. It's not actually a driver issue (although you're right saying it can't control the brightness), it's actually the Bootcamp software talking to the monitor and telling it to go to minimum brightness. If you remove it from the startup items, the brightness remains the same. A weird choice by Apple. – Django Reinhardt Feb 6 '12 at 16:29
up vote 3 down vote accepted

My research has led to the following conclusions: This is a problem that was introduced by Apple in Bootcamp 2.1 and can be fixed in the following ways:

If you're running a 32-bit version of Windows, simply install WinACD, which adds Apple Cinema Display controls to Windows Display Properties.


If you're running a 64-bit version of Windows, then things get a little more complicated, as the WinACD driver is not compatible. There are a few hacks:

  1. Boot into OSX, turn the brightness to your desired level, unplug the USB cable going into your monitor. Boot back into Windows and the Bootcamp software will now be unable to reduce the brightness over USB. (Downside: The USB ports on your monitor will no longer be useable.)

  2. Stop the Bootcamp software from starting when Windows boots. (Go into MSConfig > Startup Items and disable Bootcamp.) Then boot into OSX, turn the brightness to your desired level, and when you return to Windows, the software will no longer run and turn the brightness down to 0. (Downside: You won't be able to use the "special" keys on your Apple keyboard (e.g. volume control), and you may possibly lose other minor Apple functionality.)

The bottom line is that Apple seem to have deliberately done this. It's their software, and not Windows, reducing the brightness of the Apple Cinema Display, and it has done since they deliberately programmed it to, in version 2.1. This "feature" is present in every version of Bootcamp up to 3.3.


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I used option 1, BTW. Nice bright monitor again in Windows! – Django Reinhardt Feb 6 '12 at 15:31

Sorry to revive this old question but WinACD is broken on 64bit windows and boot camp won't play nice with most modern pc's (AHCI)

Because there was no simple solution for adjusting brightness on apple displays when using windows i wrote one.

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Apple Bootcamp seems to have an inferiority complex. The solution that I have found to make Bootcamp brightness keys work properly is:

  • Bootcamp.exe, Properties, Compatibility, Change settings for all users, Run this program as administrator.

  • Remove startup item using msconfig for bootcamp (as startup items don't work with run as admin)

  • Then create a Task Schedule for Bootcamp run as admin.

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Apple Bootcamp seems to have an inferiority complex, and needs to be run as administrator. My startup item was not loading properly (therefore my Bootcamp brightness keys were not working), so here's my solution:

  • Navigate to Bootcamp.exe. Click Properties, Compatibility, Change settings for all users, and ensure it is set to "Run this program as administrator". This should have been done in the Bootcamp install.

  • Open msconfig, ensure the startup item is selected.

  • In addition to your startup item, create a Task Schedule to run on logon of any user, and run the program as admin.

In my investigation into why the brightness keys did not work, I found that programs such as "QuickBoot" on OSX caused the issue. Seems to be some message passed from OSX, which is not done by applications such as this - stick to the normal way to boot into windows, through system preferences.

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In the future, please edit your old post instead of just posting another answer. If you've lost your user account cookie, maybe register with the site so it doesn't happen again. Your older answer will be deleted soon. – slhck Feb 14 '12 at 14:03

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