JSI Tip 5582. 'The new task has been created, but may not run because the account information could not be set'?

When you attempt to create a new scheduled task, you receive the subject error?

NOTE: Existing tasks do not start. The error code is 0x80090016-keyset does not exist.

The problem is likely the result of a corrupt %SystemRoot%\System32\Mstask.dll library.

You may have a good copy at C:\WINNT\system32\dllcache\mstask.dll.

If not, use the Recovery Console to copy the file, from the latest service pack or CD-ROM, to both folders.