Reduce display brightness (on battery): registry value DCSettingIndexComputerHKLM\Software\Policies\Microsoft\Power\PowerSettings\17aaa29b-8b43-4b94-aafe-35f64daaf1ee

Policy ID: DisplayDimTimeOutDC
Scope: Computer Configuration
Supported on: At least Windows Server 2008 R2 or Windows 7
Source: Administrative Templates (.admx) for Windows 11 2026 Update (26H2) (version 1.0)
Category: System › Power Management › Video and Display Settings

Registry

DCSettingIndex

REG_DWORDComputer

HKLM\Software\Policies\Microsoft\Power\PowerSettings\17aaa29b-8b43-4b94-aafe-35f64daaf1ee Current key

Enabled value: Depends on the option value
Element: Reduce Display Brightness (seconds):
Value type: REG_DWORD
Required: true
Maximum value: 4294967295

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Power\PowerSettings\17aaa29b-8b43-4b94-aafe-35f64daaf1ee]

; Value names and types follow the ADMX. Replace <enter value> below with your own data
"DCSettingIndex"=dword:<enter value>

CMD

:: Value names and types follow the ADMX. Replace <enter value> below with your own data

reg add "HKLM\Software\Policies\Microsoft\Power\PowerSettings\17aaa29b-8b43-4b94-aafe-35f64daaf1ee" /v "DCSettingIndex" /t REG_DWORD /d "<enter value>" /f

PowerShell

# Value names and types follow the ADMX. Replace <enter value> below with your own data

New-Item -Path 'HKLM:\Software\Policies\Microsoft\Power\PowerSettings\17aaa29b-8b43-4b94-aafe-35f64daaf1ee' -Force | Out-Null
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Power\PowerSettings\17aaa29b-8b43-4b94-aafe-35f64daaf1ee' -Name 'DCSettingIndex' -PropertyType DWord -Value '<enter value>' -Force | Out-Null