Control Event Log behavior when the log file reaches its maximum size: registry value Retention (System)ComputerHKLM\Software\Policies\Microsoft\Windows\EventLog\System

Policy ID: Channel_Log_Retention_4
Scope: Computer Configuration
Supported on: At least Windows Vista
Source: Administrative Templates (.admx) for Windows 11 2026 Update (26H2) (version 1.0)
Category: Windows Components › Event Log Service › System

Registry

Retention

REG_SZComputer

HKLM\Software\Policies\Microsoft\Windows\EventLog\System Current key

Enabled value: 1
Disabled value: 0

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\EventLog\System]

; Options (use only one)
; Enabled
"Retention"="1"
; Disabled
"Retention"="0"

CMD

:: Options (use only one)

:: Enabled
reg add "HKLM\Software\Policies\Microsoft\Windows\EventLog\System" /v "Retention" /t REG_SZ /d 1 /f
:: Disabled
reg add "HKLM\Software\Policies\Microsoft\Windows\EventLog\System" /v "Retention" /t REG_SZ /d 0 /f

PowerShell

# Common: create the key
New-Item -Path 'HKLM:\Software\Policies\Microsoft\Windows\EventLog\System' -Force | Out-Null

# Options (use only one)
# Enabled
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\EventLog\System' -Name 'Retention' -PropertyType String -Value '1' -Force | Out-Null
# Disabled
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\EventLog\System' -Name 'Retention' -PropertyType String -Value '0' -Force | Out-Null