Turn off the NVS-20 using the power switch.
Press and hold the Mode button, and turn the power switch on.
Continue to hold the Mode button for 45 seconds.
The front-panel LED's will alternate between red and green.
Let go of the Mode button and the NVS-20 will continue to boot.
The NVS-20 is now reset to default. The NVS-20 will then boot to factory settings with the default username and password.
If the reset did not work, please try the process one more time before contacting Datavideo support.