I'd much appreciate advice on whether its easier to setup a Virtual Machine on my PC (personal); or to just accept that I have to upgrade to Windows 10 and download the free copy into that OS. I really would prefer to stay with Windows 7 if I have a reasonable option using the Virtual Machine route.
Any advice or thoughts gratefully received,
The choice is really yours. From personal experience, if you are already not familiar with using WSL (Windows Subsystem Linux) in Windows 10, you will likely have an easier time and run into less issues simply setting up a virtual machine via VirtualBox or VMWare.
You can then install DSS in your VM by following the steps here: