Reformatting the hard drive will only remove recordings and some settings, if you would like to completely wipe the system, you will need to reset the device to factory settings. To do this, go to the "settings menu" and select "Load default" then select all of the items you would like to reset, finally click "apply". For more information, please take a look at our guides on the help site; https://open24seven.freshdesk.com/support/solutions/folders/43000547116