after the firmware update I was not asked for a password
No, what I was referring to was the new 'self-service password reset feature' which you may have noticed on the login page and made use of.
GUI - don't know what that is
Graphical User Interface - what you get when you point your browser at the camera or NVR.
alastairstevenson said:
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Also - on the VGA/HDMI interface, you may have created the mouse-driven 'unlock code' as an alternative / addition to the admin password entry method.
Worth checking that also. If you get in that way, you can change the admin password.
not sure what this is!
It's an alternative to using a password on the HDMI/VGA interface - join the dots up in a specific way to validate your login.
If you don't recognise it - you won't have set it up.
GUID - don't know what that is
That's a 'key file' that can be exported and saved, then later imported as a way to do a password reset.
and the last bit I am unsure what
tftp is!
It's the network file transfer protocol that's used to transmit firmware updates to the NVR over the network.
having forgotten what it was set to when installed.
It sounds like you need to hope the creative subconscious does a good job helping you to retrieve what you've forgotten.
Failing all these things - and assuming your NVR was sourced through an 'authorised channel', it may be that your next step should be to use the 'lost password' feature of SADP where the exported file is sent to Hikvision tech support, they send you one back which you then import. Unless they decide from checking the serial number that they won't help - which is pretty common, it seems.
Just for future interest - this is the VGA/HDMI 'join the dots' login method:
