How can I clear all Windows event logs using built-in tools?

You can use `wevtutil.exe`, which is included by default in Windows 7 and later. Running `wevtutil cl {LogName}` (e.g., `wevtutil cl Application`) deletes all entries in that log category. For more advanced clearing options, you can also use tools like NSA DanderSpiritz, which offers commands like `eventlogclear -log Application`. For details on deleting single entries, see Penetration Techniques - Deleting Single Windows Log Entries.