>Does the Windows NT Server with SQL Server running on it use ODBC or does only the client computer use ODBC?
>

SQL Server doesn't talk to itself via ODBC; ODBC (as well as things like DAO, RDO and ADO) is used for other processes on the same machine, and for remote machines, to talk to SQL Server. IOW, if you have an NT Server running SQL Server, and another process, say a VB application running on the same box, would use an ODBC or ADO connection to talk to SQL Server, just like any other SQL Server client. the fact that it runs on the same physical machine doesn't change the interface.

>Is it a problem if the server has an older version of the SQL ODBC driver than the client?

The ODBC driver is invoked client side, not server side; an older ODBC client on one machine shouldn't have an effect on another machine's access.