It appears I have solved my camera problems. To help other with similar problems, I have explained my solution below.
I have found out why my cams did not work before and gave error messages instead. These hikvision cams (version 5.3) came with no default password set.
Detecting the cams and their settings using SADP tool, worked differently than older version hikvision cams did.
The first thing required is that you set a 'Super User' default name and password, which I did. Nowhere, in this process did it explain that this 'Super User' had nothing to do with camera password.
The cameras' password setting needs to be 'admin' and its password was separate from that which applied to the 'Super User' password.
I can just imagine how many people got tripped up by this if they had experience with previous versions of hikvision cameras.
The cameras work just fine now. I have indeed set the cameras addresses to not use DHCP, so that the addresses do not change.
My modem/router, supplied by my service provider 'Brighthouse', is an 'ARRIS modem/router' combination with 4 output ports. My cameras are connected to an 8 port POE switch which is plugged into the 'ARRIS modem/router'.
On to a separate question:
I have the iVMD-client installed on C:
Is there anything to be gained by using E: or F: instead? Please understand that all these drives are super fast solid state SSD?