In Windows Server 2003 (SP2), a task is created, and the assigned “Run as” user has minimal privileges. Upon checking the log (“Scheduled Tasks” window, Advanced menu…View Log), the start reason (or lack thereof) is “Access Denied”.
Plain users do not have access to cmd.exe. In this particular case, I was trying to run a batch file. Without an interactive session, the default permissions for cmd.exe did not allow the “RunAs” user to execute it.
Add the “RunAs” user to the local group: TelnetClients
By default, this group has permissions to cmd.exe