I am sick of Swann software. I have it in a retail environment. If I need to check cameras back to check shoplifting I have to select which of the cameras with only 4 at a time. But the time I click back and have selected the time and then reselected the time to the point. The person has disappeared. I don't mind a subscription but I basically want the best for retail shop lifting watching. I would replace the NVR if it can't be flashed. The cameras I am hoping are compatible.