Topic Last Modified: 2007-03-16

Microsoft Exchange Server 2007 setup cannot continue because its attempt to install the Client Access Server or Unified Messaging server roles failed because the Distributed Transaction Coordinator service is not started on the target computer.

Exchange 2007 setup requires the computer that you are installing Microsoft Exchange to have the Distributed Transaction Coordinator service status set to Started.

The Distributed Transaction Coordinator service provides services designed to ensure successful and complete transactions, even with system failures, process failures, and communication failures.

Each computer participating in a distributed transaction manages its own resources and data and also acts in concert with other computers in the transaction. Above all, a distributed transaction must commit or abort its work entirely on all participating computers. The Distributed Transaction Coordinator performs the transaction coordination role for the components involved and acts as a transaction manager for each computer that manages transactions.

Both the Client Access Server and Unified Messaging server roles have dependencies on the Distributed Transaction Coordinator service.

To resolve this issue, verify that the Distributed Transaction Coordinator service status is set to Started on the local computer, and then rerun Microsoft Exchange setup.

To set the status of the Distributed Transaction Coordinator service to 'Started'
  1. Right-click My Computer, and then click Manage.

  2. Expand the Services and Applications node, and then click the Services node.

  3. In the right pane, locate the Distributed Transaction Coordinator.

  4. Right-click Distributed Transaction Coordinator, and then click Properties.

  5. Set the Startup Type to Automatic and the Service status to Started.

  6. Click Apply, and then click OK.