>Hi
>
>To be more specific for at least one basic case,
>
>If I connect to a second database in SQL 2005 it works fine
>If I do the same in SQL 2008 R2 I get the following message:
>Error 0:
>Connectivity Error [Mocrosoft][ODBC driver Manager] Data Source Name not found and no default driver specified.

What Bill said, which means you'd have to connect to each separately and keep two handles.

There are more complicated ways - if you need to use tables from both servers in the same statement, you can have the servers talk to each other. That requires that one server pulls from the other - see in BOL about connected servers. In that case, you connect to one server, and it pulls data from the other server, combines them with its local data, and returns a result set to you.