Specify the maximum log file size (KB)
This computer policy limits the size of the file that stores the Windows System log.
since 0.9.8.11
Purpose
Show registry keys (1)
HKLM\Software\Policies\Microsoft\Windows\EventLog\System\MaxSize
This computer policy limits the size of the file that stores the Windows System log. MaxSize is a REG_DWORD value whose data represents the maximum file size in kilobytes.
The supported range is 1024 through 2147483647 KB, corresponding to 1 MB through approximately 2 TB. When this policy does not define the limit, Windows uses the locally configured maximum log size.
Notes
Security
Setting the limit too low can reduce the amount of system, driver, and component history available for troubleshooting or forensic analysis. Older records may be overwritten sooner. If a separate retention policy prevents overwriting, new events can instead be lost after the log reaches capacity.
This setting does not change access permissions for the System log or determine which events Windows records.
Possible side effects
A larger limit can preserve more event history but allows the log file to consume more disk space. A smaller limit causes the log to reach capacity more frequently.
Notes
MaxSize controls only the size boundary. Separate retention and automatic-backup settings determine whether Windows overwrites old records, discards new events, or backs up a full log when that boundary is reached.
Microsoft documentation
Microsoft Learn: EventLogService Policy CSP