The SQL Server drivers support two-phase commit and can fully participate in a distributed transaction when the transaction environment parameter convertAllToDistributed is set to true.

You can use SQL Server with its two-phase commit capability both under MTS, and directly through an XA connection. In both cases, Microsoft DTC must be running on the server.

If you are working under MTS, start an OLE transaction. The SQL Server data source is automatically included in the distributed transaction.
If the connection to the data is through an XA connection, the connection is made automatically. The daemon server mode must be configured to Single-client mode.

To use distributed transactions from an ODBC-based application, ensure that AUTOCOMMIT is set to 0.