1. Start Task Scheduler
2. Create a new task without changing user and user group (anything else can be specified at this time).
3. Export this task to an xml file (the Scheduled Task configuration file)
4. Delete this task.
5. Open the exported task using a text editor.
6. Find the following section:
7. Change DomainName\UserName (ex. Companyname\administrator) accordingly. Note: DomainName is the NetBIOS name of the domain.
8. Save the file.
9. Import the task into Task Scheduler."