Adding users to local security groups using Group Policy
You may find that you need to add users to one or more local groups, such as Power Users or Administrators, on their computer. While you can do this fairly easily on a case by case basis, it's a lot more difficult to do in a large distributed environment
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Read the complete post at http://www.expta.com/2011/02/adding-users-to-local-security-groups.html