Add an existing active directory user to the SBS 2011 users console

Open ADSI Edit from administrative tools
Right click ADSI Edit and click Connect to… and click Ok keeping the default values
Browse to the user you want to import to the SBS 2011 Console
Right click the user, and select Properties
Find the setting msSBSCreationState and set the value to Created

Sources

http://stevehardie.com/2011/08/adding-an-existing-ad-user-to-the-sbs-2011-console/

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