I am a Winclone User for many years.
I want to install Bootcamp on my new iMac2020 on the external thunderbolt SSD.
I made a clean new bootcamp installation on the internal drive (ssd) first.
After Installing I tried a boot and installed all BC Drivers & Windows updates.
Then I made an Image File from the bootcamp partition with Winclone8 and restored this Image to my external SSD.
This SSD was not bootable (inaccesable boot device). So I tried to inject the SSD Driver from the Winclone8 menu regarding your manual.
This fails with this message: No Driver Found (but it was there)
After that I tried to inject the driver from the Windows command prompt like described here:
dism /Image:D:\ /Add-Driver /driver:c:$WinPEDriver$ /recurse
But this operation failed again.
Message was something like:
In my case there was no drive “D:”
I changed the D: to X:
dism /Image:X:\ /Add-Driver /driver:c:$WinPEDriver$ /recurse
“you tried to modify a installed Windows”
I have no idea what went wrong.