Paul,

Are you running the regsvcs.exe tool matching the version of the .NET framework you compiled your assembly against?

IOW, if you compile your assembly with v1.1, then you must use the regsvcs.exe tool from the v1.1 distribution. Otherwise the tool will not find the classes.

 I am am trying to register my DLL in the COM+ Catalog. To do this I am taking the manual approach and using the regsvcs.exe tool provided with the .net framwork.

 However when I regiser the dll it comes back that I have derived classes found in the assembly and won't register, saying that classes must be public, concrete and have a default constructor. Why is this happening? As far as I'm aware I haven't got any derived classes apart from the serviced component which is required. Below is my code for my class:

 using System;
 using System.Data;
 using System.Data.SqlClient;
 using System.EnterpriseServices;

 namespace StepByStep7_1
 {
      public class NorthwindSC : ServicedComponent
     {

         private SqlConnection sqlcnn;
         private SqlDataAdapter sqlda;
         private DataSet ds;

         public NorthwindSC()
         {
             // Create a connection to the
             // Northwind SQL Server database
             sqlcnn = new SqlConnection("data source=(local);initial catalog=Northwind User ID = SAassword = *********");
         }

         // This method executes a SELECT query and
         // returns the results in a DataSet object
         public DataSet ExecuteQuery(string strQuery)
         {
             // Create a SqlDataAdapter object to talk to the database
             sqlda = new SqlDataAdapter(strQuery, sqlcnn);

             // Create a DataSet object to hold the results
             ds = new DataSet();

             // Fill the DataSet object
             sqlda.Fill(ds, "Results");
             return ds;
         }

         // This method updates the database with the changes in a DataSet object
         public int UpdateData(DataSet ds)
         {
                 // Update the database and return the result
                 SqlCommandBuilder sqlcb = new SqlCommandBuilder(sqlda);
                 return sqlda.Update(ds.Tables["Results"]);
         }
     }
 }

 Many thanks for your help in advance

 Paul