If you are playing around with various versions or instances of MS SQL Server you may hit this problem... this worked out for me. From the command line regsvr32 "\80\Tools\Binn\sqldmo.dll regsvr32 "\80\Tools\Binn\sqlmmc.dll regsvr32 "\80\Tools\Binn\sqllex.dll regsvr32 "\80\Tools\Binn\sqlns.dll