You will be prompted for the account password when you click the Ok button to confirm the task property changes. Click the “Change user or Group” button and retype your service account name and click Ok. Then click Ok on the task properties and you should be prompted to enter the service account’s password. Note that you have to choose “Run whether user is logged on or not” in the Security Options section right in order to set the password. Otherwise it’ll use the authentication token of the logged in user at the time the event fires.
