I have created a backup task that I am running from the Vista Task Scheduler as discussed here. The backup task is setup to use an Acronis Backup Location and is supposed to do differential backups, creating a new full backup after each six differentials. However, when this task is invoked by the Vista Task Scheduler (or manually from a command prompt for that matter) it always creates a full backup with a new file name. If the backup task is initiated from within the Acronis GUI it works properly and creates a differential backup if a full backup already exists. Any ideas why this won't work properly when initiated outside of the Acronis GUI?