If you choose a migration installation, you must thoroughly plan the migration and then prepare your source server
and destination server as described in the information at03 http://go.microsoft.com/fwlink/?LinkID=193017. After your preparations are complete, follow the steps in the wizard to
migrate to Windows SBS 2011 Standard.
NOTE: After you prepare the source server for the migration, you have 21 days to complete the migration process and shut down the source server.