Make someone an administrator in Windows Server 2008 R2.

The following is like this yet different:

1. right-click on "My Computer" or the comparable icon and pick "Manage"
2. at the Computer Manager pane that appears navigate to: Configuration > Local Users and Groups > Groups
3. right-click on the "Administrators" group and select "Add to Group..." from the menu which appears
4. add individuals here at the "Administrators Properties" window which pops up