Right click on the background and select CREATE NEW TASK (or select it from the ACTIONS pane on the right)
On the GENERAL TAB, enter whatever task name and description you want
On the GENERAL TAB, you will likely want to click CHANGE USER OR GROUP button (middle right) and have the job run as someone else
like a service account you created in Active Directory just for this task
note the you can use the SYSTEM account for many tasks but after you set it to run as SYSTEM you can not longer change the task because you don’t know the password
On the TRIGGERS tab, click the NEW button and set whatever trigger you want, most commonly a time of day