My favourite GP tool is by far the rsop.msc (Resultant Set of Policy) snap-in. Access the rsop.msc tool by either typing the command at a command prompt or typing the command in the Run box.

rsop will show you exactly what settings are being set by Group Policy and which Group Policy Objects are enabling those settings.

rsop builds an up-to-date view of the objects applied – so any changes you make to GPO’s will need to be refreshed on the client/server before they will appear in rsop. This means you need to run the gpupdate /force command to refresh the GPO and ensure your rsop output is up-to-date.