First make sure that the service isn't being stopped by a user or some other process:
- Check the Application log in the Event Viewer to see if there's a message from the Arcana Scheduler indicating that it's being stopped.
- Check the System log in the Event Viewer to see if there's a message from the Service Control Manager indicating that it's stopping the Arcana Scheduler service.
If not, check to see if there is a Dr. Watson crash dump or log being produced. Run "drwtsn32" from Start|Run and note the location of the Log File Path. Now open the log file in that directory and see if there's a fault being reported for "adscheduler.exe".
One thing you can try is to disable Data Execution Prevention for adscheduler.exe. See www.arcanadev.com/support/kb/K00000242.aspx
for instructions on how to do this, but also include "adscheduler.exe" when adding exceptions.
The Arcana Scheduler itself would not be changing its own startup type. So either Windows is changing the startup type for some reason, or some other software is. What version of Windows are you running?
Is there a pattern to when/how often this occurs?