You can reset the password of DVR or NVR via Guarding Vision.
- 
                On the user login interface of the device, click Forgot
                        Password.
            
- 
                On the password reset type interface, select Verify by Guarding Vision.
                
                    The QR code will be generated on the local GUI of the device. 
 
- 
                Go to the Guarding Vision Mobile Client, and then tap  to enter the Reset Device Password page.
            
- 
                Scan the QR code.
                
                    A verification code will be displayed on the Mobile Client. 
 
- 
                Go to the local GUI of the device and enter the received verification code, and
                    then click OK to continue.
            
- 
                Create a new password and then confirm the password on the local GUI of the
                    device.