Compare GPOs with Microsoft Policy Analyzer

1. Download Policy Analyzer (part of the Microsoft Security Compliance Toolkit) from Microsoft.

2. Back up the GPOs you want to compare, from Group Policy Management (right-click > Back Up) or with PowerShell:

Backup-GPO -All -Path C:\GPOBackup

3. Import them: in Policy Analyzer click Add... > File > Add files from GPO(s), select the backup folder and import it as a rule set.

4. Compare: tick the rule sets and click View / Compare. Conflicts and differences are highlighted, and you can export the result to Excel.

Tick Local policy or Compare local registry to compare against what is actually applied on the machine. It's also handy to compare your GPOs with Microsoft's security baselines, which come in the same toolkit.