Currently there is no way to do what you are asking. I have an NB3 and a NB2. Neither one gives you that option.
A work around would be to set the recordings to auto delete after a set period of time. That option is in the settings on all the PVRs.
You can also delete everything by doing a factory reset. That will clean out the drive, but it will also reset all your timers and settings.
Here's the multi-item deletion methods I know of:
You can delete one recorded program at a time; however you can erase all recorded programs by formatting the hard drive. Please follow steps below to format hard drive;
Within a minute the box will reboot itself. When the reboot process is complete the hard drive will be empty.
Let us know if you require futher assistance!
I believer there is an option now to allow you to delete multiple recordings at the same time.
Yes, that's right. Instructions described by me here: http://communityforums.rogers.com/t5/forums/forumtopicpage/board-id/PVR_settop_boxes_remotes/message...