You can click the 'empty epg' button to delete all the tv listings, but still have the channels available (to watch / record etc).
If you're saying you want to set it up from scratch, you can delete the npvr.db3 file, but you'll then need to scan your device channels etc to get it functional again.
Having a senior moment -
1. am recording an American Football game - 3 1/2 hr. Some time back, had a 1 second power bump 2 hr into the recording, blew up the file.
2. If I am recording in 1/2 hr segments, I can begin watching the 7pm recording at 7:30, whilst the recording continues, without waiting til 10:30 pm.
Thanks again