Why doesn't brightness change on external display on Windows 11?

Question

I have a laptop with an external display and when I try to change brightness in Windows 11 it changes only on built in display.

Night light works thought.

I'd change brightness with monitor menu, but HDR on doesn't let me do this, and it still takes too much time. I want to change the brightness on both monitors with Windows control panel slider.

• Laptop: Maibenben m543
• External display: DEXP DF24H1

Answer 1

Yes, indeed Microsoft has failed to provide adequate controls for adjusting external monitors. I own several different laptops and external screens and Windows is not able to independently control the screen brightness.

However, there are several excellent solutions.

• Twinkle Tray (Free and open-source software)
• Monitorian (Free and open-source software)
• EasyMCC (Free, Non-open-source software)
• ControlMyMonitor Nirsoft (Free, Non-open-source software)
• Dell Display Manager (Free, open-source software)

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Other Related Questions:

• In laptop with Windows 11 I can adjust screen brightness from Windows. In a desktop with Windows 11 I can't --- should I buy a new screen?
• How can I assign a keyboard shortcut to increase/decrease the brightness of both my monitors?
• Enlarging the brightness range on Windows 11
• Why doesn't brightness change on external display on Windows 11?
• Dim screen below minimum brightness level
• Brightness on one of dual screen monitors keeps lowering
• Natively controlling Dell external monitor brightness in Windows 10

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Unfortunately I have not found the correct way to change brightness for external screen using PowerShell.

Looking at:

1. https://learn.microsoft.com/en-us/windows/win32/wmicoreprov/wmisetbrightness-method-in-class-wmimonitorbrightnessmethods
2. https://devblogs.microsoft.com/scripting/use-powershell-to-report-and-set-monitor-brightness/
3. https://learn.microsoft.com/en-us/windows/win32/wmicoreprov/wmimonitorbrightness
4. https://learn.microsoft.com/en-us/windows/win32/wmicoreprov/wmimonitorbrightnessmethods

I can only adjust the internal (primary) screen, using:

# Shows ALL Displays
Get-Ciminstance -Namespace root/WMI -ClassName WmiMonitorBasicDisplayParams
List ALL Displays (InstanceName) [4]
Get-Ciminstance -Namespace root/WMI -ClassName WmiMonitorDescriptorMethods
The following PowerShell example retrieves the serial number of multiple monitors.
Get-WmiObject WmiMonitorID -Namespace root\wmi | ForEach-Object {($.UserFriendlyName -ne 0 | foreach {[char]$}) -join ""; ($.SerialNumberID -ne 0 | foreach {[char]$}) -join ""}
Brightness in % and Timeout in seconds.
To set the brightness to 80% and request that it in 2 seconds.
$m = Get-CimInstance -Namespace root/WMI -ClassName WmiMonitorBrightnessMethods
Invoke-CimMethod $m -MethodName WmiSetBrightness -Arguments @{Brightness = 80; Timeout = 2}