I have a problem with my windows 7 laptop automatically waking after I put it to sleep and then I find it later with the battery drained. I tracked down the culprit using the "powercfg -lastwake" command to be a Backup task in the "Windows Server" section of the task scheduler.

I have tried unchecking the "Wake the computer to run this task" checkbox for this task, but after I do this and reboot, the box is always rechecked again. How can I make this setting persist? I have full admin rights to this laptop, but it is on a domain.

Edit: I looked into the domain policy settings as suggested by Dave below and did not find any policies related to scheduled task settings. Any other ideas?