Run CD\Sql_esp\ xp_ndo.exe from the first installation CD and uncompress the file xp_ndo.dll in the folder BINN of the SQL Server (Esempio: C:\Programmi\Microsoft SQL Server\MSSQL.1\MSSQL\Binn )
Open Enterprise Management
Select Servername / Databases / master Databases
Select master / Programmability / Extended Stored Procedures
New Extended Stored Procedure …
Browse to xp_ndo.dll
Call the procedure xp_ndo_enumusergroups
Assign to the Public role the Execute rights