I had to waste half an hour to make this simple schedule task to work. I thought I should document this here.
Steps 1: Make sure your power settings are set to allow sleep timer.
Go to power options -> plan settings -> change advance power setting -> sleep -> allow sleep timers. (Do this for all power options).
Set the task to run with highest privileges and wake the computer to run this task under conditions.
"Run whether user is logged on or not": If this radio button is selected, tasks will not run interactively. To make a task run interactively, select the Run only when user is logged on radio button." I guess the concept here is that a task requiring a user interface is simply not going to be allowed to present that user interface to a different user (or to someone passing by the computer when no user is logged-on).
See below screen snapshots: