At the moment of starting the session where the user screen and password appears, in the lower left you have to double click with the mouse brings a hidden button .. this must be done directly in the DVR

Then another screen appears with your serial number, where you will be asked for the password you generated.
THROUGH HIKVISION TOOL you connect to the same network or directly to the UTP cable dvr, once you have the key go to the bottom where it says Password DEFault ..

Greetings .. I hope you have already served ..