SYMPTOM:
After the machine hosting the Strategy Narrowcast Server 9.x is either started or rebooted, the Strategy Distribution Manager service does not start automatically. Though, the Strategy Narrowcast Server system is successfully able to start through the Strategy Narrowcast Administrator console.
CAUSE:
The Strategy Distribution Manager service was set to a startup type of 'Manual'. This can occur if it was manually changed while the Strategy Narrowcast Server system was running, or the system was stopped prior to the machine rebooting. In the later case, Strategy Narrowcast Server is behaving as expected.
Strategy Narrowcast Server was designed so that if a manual stop command is issued to the system, the Strategy Distribution Manager service startup type is set to 'Manual'. After all, a manual request was provided to stop the system. When the system started the startup type is changed to 'Automatic'. This said, if the Strategy Distribution Manager service is stopped before the machine is rebooted, the service will be set to 'Manual' and remain in 'Manual' after the machine is back online.

ACTION:
In order for the Strategy Distribution Manager service to start automatically after the machine is rebooted, the service must be running before the machine hosting Strategy Narrowcast Server is rebooted.
Refer to the following Strategy Knowledge Base technical note for more details on the Strategy Distribution Manager service behavior:
KB11537 - What are the startup types for the Strategy Narrowcast Distribution Manager and Execution Engine?