Task Scheduler not recognising user

Hi,
I'm trying to shutdown a computer automatically every evening. I have programmed a shutdown item in the Task Scheduler but when it gets to the user information it doesn't recognise my user. The error message I get is "Unable to establish existence of the account specified" while I'm creating the scheduled task. I have tried making a new user but it doesn't help the issue. I have read other posts saying that xp has issues with user recognition and have not seen a successful resolution yet.
Does anyone know of a solution to this?
Thanks!

 

Problem Solved

We worked out that we needed to add a password to our username to make Task Scheduler work.

We then went to the START menu and chose RUN and typed: control userpasswords2 to be able to turn on automatic logon.

Tried to link to articles that helped but we haven't posted enough.

 

thanks for the update, glad your issue is resolved.