it should only do it the first boot. it will backup all title updates as well, depending on how many you have and how fast your drive is, this may take a while. if you really want to, you can change the setting in the db on a pc, using a SQLite tool (like SQLite Database Browser) open the settings.db, select the SystemSettings Table and change TUScanAtBoot to 0   This might have a negative effect on TU management from aurora (you would have to redownload TU's you already had