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I have setup a dualscreen setup for my notebook with an ATI video card (ATI mobility radeon hd 5470) using Catalyst Control Center.

The monitor extends the desktop of the notebook's screen. This works great.

I am running on windows 7 and have set it up to not do anything when I close my laptop's lid (case) other than dim the notebook's display.

However, when I do close the lid (notebook's display), the second monitor suddenly changes and I believe it starts behaving as the primary monitor.. I do not want this to happen.

So, how do I setup my dualscreen setup so that it won't set the secondary monitor as the primary one when I close my laptop's lid?

UPDATE: this video shows exactly what my problem is: http://www.youtube.com/watch?v=Q1ygNHbqI2g

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Out of curiosity, why do you want this behavior? Obviously if the internal screen is the primary you can't use it with the lid closed so this seems rather impractical. –  Shinrai Mar 8 '11 at 15:12
    
@Shinrai because if I want to use the primary one I will open the lid again. At the moment it is VERY very very annoying because whenever I watch a movie on my secondary screen I just cannot close the lid of my laptop. I now added a bounty. –  Tom Mar 10 '11 at 15:27
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@Tom - If you're always using the external, but only sometimes using the internal, shouldn't the external be set as primary? (You get better video rendering on the primary display anyway due to some artifacts in the way most video drivers for Windows are written.) –  Shinrai Mar 10 '11 at 15:50
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@Tom - You implied it. ;) To my knowledge this is dependent on your laptop and I'm not aware of any that won't do this; most of them are hardwired to disable the internal screen with the lid closed (like, as far as the operating system is concerned it's not even there). If you can still see it in Display Properties with the lid closed you MIGHT have a chance. I'm just suggesting examining your habits because there may not be a way to do this, period. –  Shinrai Mar 10 '11 at 18:27
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@Tom - Right, but when you power off a monitor the machine still thinks it's attached. Laptops are designed to make the operating system think the display vanished entirely because most people want the exact opposite of your desired behavior (that is to say, if the lid is closed they don't want any windows over there!). –  Shinrai Mar 10 '11 at 22:32

2 Answers 2

up vote 2 down vote accepted
+50

As Shinrai said, it's probably the notebook's hardware shutting off the monitor (and detaching it) when the lid closes, regardless of what the OS is set to.

Check the notebook's BIOS settings and see if there's any options you can control about the monitor turning off on lid-close in there.

If not, then you're pretty much done-for if you need the internal to be the primary, because if you don't have a primary, you can't have a secondary; so the secondary monitor will always automatically become the primary when the primary is disconnected/detached (via hardware).

Add: This is a guess:

Perhaps try setting the notebook's monitor driver to 'Generic Plug and Play Monitor' or alike. Perhaps that will break the ability for Windows to know it's 'attached' state.

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Solution from prevent monitor switching when closing laptop lid :

Go into registry and create a new DWORD called "LidAlwaysOpen" set value to "1" in
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\"YourDisplayGUID"\0000\

Some user have been reported this will work only for first lid closure, but not for subsequent ones.

The thread annoying extended desktop in windows 7 offers another possible solution :

  1. Open device manager
  2. In "System devices" find "ACPI lid"
  3. Open "ACPI lid" properties, and go to "Driver" tab.
  4. Select "Update driver"
  5. Choose "Browse my computer for driver software" and "Let me pick.." uncheck "Show compatible hardware"
  6. And now...in "Manufacturer" select "(Standard system devices)" and model: "Volume manager" (yes, "Volume manager")
  7. Next, next, restart the system and it works!
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the first method does not seem to have any effect. The second one appears to set an invalid device on purpose (I rather not do this for something so minor). –  Tom Mar 12 '11 at 11:40
    
The second method in effect negates all lid actions. It is probably possible to create batch files to flip between the two drivers using DevCon. –  harrymc Mar 12 '11 at 11:59
    
I am amazed that such an important feature is lacking though.. I cannot see how anyone would want his or her screens to completely re-organize when temporarily closing the laptop's lid when you wish to only see what's on the secondary monitor. –  Tom Mar 12 '11 at 22:17
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@Tom: If my primary monitor becomes physically unavailable I sure hope my secondary monitor would be available as a primary, and thank goodness Windows 7 does it automatically and gracefully. ;) –  Ƭᴇcʜιᴇ007 Mar 13 '11 at 2:56
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I agree with @techie007: Win7 does here what is right in most cases. They apparently didn't think your case is important enough to even add it as option, so you are obliged to force it through. –  harrymc Mar 13 '11 at 9:26

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