I'd recommend that you use the Task Scheduler... Here is how you'd do it:
Go to Administrator Tools, Task Scheduler, and use the "Create Task" (not the Create Basic Task)
On the General tab
Give it a name
Click on the "Run whether user is logged on or not"
(It will prompt you for a password)
On the Triggers tab
Create a new Trigger
Use the "disconnect from user session"
Click on the "Connection from Local Computer"
On the Actions tab
Add a new Action
Select a path to your batch file