In order to allow “normal user” accounts to invoke tasks created in Task Scheduler, you will need to assign the “Log on as a batch job” user right and also edit the ACL to change the current directory and all subdirectories by granting full control user access rights, as below:
cacls "C:\Windows\Tasks" /e /t /g "<user account/security group>":F
This will now allow you to run tasks as a “normal user”, providing the user account has privelages to perform the actions within the task itself.
Deans Blog 