You receive error message 0x80090016 when you try to schedule a task
First, try this Microsoft article.
That didn’t work for me. It turns out that the DNS was pointed to a public ISP server instead of pointing to the domain controller as it should.
This was in the event log:
Event ID 1053 Source: Userenv
Windows cannot determine the user or computer name. (The specified domain either does not exist or could not be contacted. ). Group Policy processing aborted.
Changed the DNS and rebooted and everything works now.
1. Delete the offending “SYSTEM” account tasks in Task Scheduler.
2. Stop the Task Scheduler
3. Delete all files in C:Documents and SettingsAll UsersApplication
4. Restart the service (I’d restart the server as soon as possible, too).