This is good to have as a reference - common failure codes for scheduled tasks:
0 or 0x0: The operation completed successfully.
1 or 0x1: Scheduled task ran, but the application returned an error.
2 or 0x2: File not found.
10 or 0xa: The environment is incorrect.
0x41300: Task is ready to run at its next scheduled time.
0x41301: Task is currently running.
0x41302: Task is disabled.
0x41303: Task has not yet run.
0x41304: There are no more runs scheduled for this task.
0x41306: Task is terminated.
0x8004130F: Credentials became corrupted (*)
0x8004131F: An instance of this task is already running.
0x80070002: similar to file not available (2147942402)
0x8007010B: Action 'start in' directory can not be found.
0x800704DD: The service is not available (is 'Run only when an user is logged on' checked?)
0xC000013A: The application terminated as a result of a CTRL+C.
0xC06D007E: Unknown software exception.