The second, and more comprehensive, way to restore GPOs is by launching the Manage Backups tool. You do this by right-clicking on the Group Policy Objects folder, and selecting Manage Backups...:

Here, you can see all of the backup files and versions that are sitting inside my C:GPO_Backups folder. This tool is definitely the way to go if you need to restore multiple GPOs. All that you need to do is select a backup copy, and click the Restore button. This rolls the GPO back to the settings defined inside the backup. As you can see, the View Settings... button is also available in this tool, and there is a neat checkbox to Show only the latest version of each GPO. If you are confident that the latest backup you took is the one you want to roll back to, selecting this box really narrows down the number of objects that are presented to you inside this screen.

When trying to restore a GPO that has been deleted from Group Policy, the Manage Backups tool is the right place for you. By browsing through the backup files for the GPO that was deleted, you can very quickly and easily restore the GPO right from this interface.