How to increase event log retention on windows

Configuring Security Event Log Size and Retention Settings

Security event log size and retention settings can be configured in each computer or configured via a GPO to all target computers.

Local Configuration

1. Open Run (Start -> Run), type eventvwr.msc
2. Right click "Security" log(Event Viewer -> Windows Logs -> Security log) and select "Properties"
3. Configure "Maximum log size" as defined below in the table
   
4. Configure "When maximum event log size is reached" retention method for security log to “Overwrite Events As Needed”
   

GPO Configuration

1. Open GPMC
2. Edit the corresponding GPO (FIM on DomainControllers, FIM on Member Servers)
3. Navigate to Computer Configuration → Policies →  Windows Settings → Security Settings →  Event Log
4. Configure "Maximum security log" size as defined below
5. Configure "Retention method for security log" to “Overwrite Events As Needed”
   

Recommended Security Log Size

Role	OS of the target computer	Log size(MB)
Domain Controller	Windows Server 2003	307
Domain Controller	Windows Server 2008 and above	1048
File Server	Windows Server 2003	307
File Server	Windows Server 2008 and above	4194
Member Server	Windows Server 2003	307
Member Server	Windows Server 2008 and above	1048
Workstation	Window XP	307
Workstation	Windows Vista and above	1048