Windows Scheduled Task - Error 2147943711 for "on startup" task

Solution 1:

You should not be specifying a user account under which to run the task if you do not want to save the password. Run it as system if that would work or save the user account and password with the task.

Solution 2:

My solution (noted here to give others help in addition to the accepted answer):

The task used to run under a local user. Run whether user is logged or not ticked; Do not store password not ticked.

Everything was OK until we renamed the machine - I then had to reassign the user which the job runs under to be the same user - but under a different computer.