Update Windows/BackupGPO.md

Windows/BackupGPO.md

@@ -82,3 +82,11 @@ Get-ChildItem -Path $path -Recurse -Force | Where-Object { $_.PSIsContainer -and
 
 Remove-Item -Path $temp -Force
 ```
+
+## possible command for the cronjob on the linux system
+
+You can run this without the `-delete` and you will see affected files by the filter.
+```bash
+# -mtime +10 => older than 10 days
+find /backup/gpos -mtime +10 -type f -delete
+```