The first way to utilize Group Policy Loopback Processing is to configure it in Merge Mode. When loopback is configured as such, you will get a merging of GPO settings. During system startup, the computers behave in the normal Group Policy fashion, looking at their GPOs and applying all of their Computer Configuration settings. Then the user logs in, and all of the GPOs that have User Configuration settings go ahead and apply. Again, this is all normal behavior.

The new part is that after user settings have applied themselves, Group Policy then goes back and runs through the GPOs again. It looks back through all of the GPOs that are applied to the Computer, and then processes all of the User Configuration settings that are inside those GPOs. See, the computer is pretending that it is a user!

Now you can start to see the benefits here. You likely already have GPOs that are applied to the computer accounts to do computer-ish things. Then, you also have GPOs applied to user accounts to do user-ish things. Now you need to make sure that these special computers always receive the same settings, no matter which user logs in. Rather than try to figure out how you are going to link this GPO to apply to all users, but only to specific computers, you can instead utilize those computer-ish GPOs that you already have, include some User Configuration settings, and the computer will then force those User Configuration settings no matter which user is logging in!