I would just mount the drives and then use backupmenu to access the / filesystem, since you dont have clean backups, and delete the two files you made. /etc/udev/rules.d/98-bnep0.rules /etc/udev/bluenet.sh Then try to reboot. If that doesn't fix the problem then it seems that other files have been edited or deleted. If the above doesn't work I hope you have clean backups. If deleting the two files doesn't work then it is something other than the BT tethering that has gone wrong.