One of the critical steps in achieving a Lockdown environment is identifying all the users in your domain that have local admin rights on their desktops so you can remove those permissions. One way to easily identify such users is through Scriptlogic's Security Explorer product. You can download a free 30-day trial of ScriptLogic’s
Security Explorer tool to search your domain for users with local admin rights. Please use the following link to refer to the Knowledge base article for step by step instructions on how to do that using Security Explorer.
http://na5.salesforce.com/_ui/selfservice/pkb/PublicKnowledgeSolution/d?orgId=00D300000000xmc&id=50170000000WTKf&retURL=/sol/public/solutionbrowser.jsp?cid=02n700000001hLk&orgId=00D300000000xmc&t=0&ps=1
With a full licensed version of the Security Explorer, you can also remove those users from local admin group. Refer to the product page through the following link to understand all the its capabilities.
http://scriptlogic.com/products/security-explorer/
Avinash Kodey
Director Product Management
ScriptLogic