Following on the heels of our clarification of GPOs versus GPO links, let's discuss that GPO link warning message that you have undoubtedly seen 100 times already as you have started clicking around inside GPMC. By default, unless you have already turned it off, every single time that you click on a GPO link, you will see the following warning displayed:

This is super annoying, and thankfully it is easily disabled by checking the little box that says Do not show this message again. However, it is very important to read this message at least once, and to take it to heart. This warning is telling you, in case you didn't know, that while you have clicked on a mere piddly link to a GPO and not selected upon the GPO itself, changes that you make here will change the GPO itself! Remember, a GPO is only stored in one centralized location. There may be numerous links to that same GPO, which sometimes makes it appear as if they are separate GPOs. If you were to click on a link to a GPO that is listed under an Accounting OU and make a change, and that same GPO is linked to human resources, any settings that you change will affect human resources as well.

If you have disabled this message and want to re-enable it for the sake of a new administrator or simply to start giving yourself that reminder once again, it is easily done by opening GPMC and visiting the View menu. Open View | Options | General and re-select the box for Show confirmation dialog to distinguish between GPOs and GPO links: