This policy setting controls Event Log behavior when the log file reaches its maximum size. If you enable this policy setting and a log file reaches its maximum size new events are not written to the log and are lost. If you disable or do not configure this policy setting and a log file reaches its maximum size new events overwrite old events. Note: Old events may or may not be retained according to the “Backup log automatically when full” policy setting.

1. Registry path is:

   HKEY_LOCAL_MACHINE -> Software -> Policies -> Microsoft -> Windows -> EventLog -> Security # Retention

2. The Administrative Template path is:

   Windows Components -> Event Log Service -> Security

* Making mistakes while changing registry values can affect your system adversely. We recommend you to create a System Restore point before making registry manipulation. If you're new to Registry Editor, read this beginner's guide.

** To locate the registry and administrative template path, checkout beginner's guide.