Thank you for the message Fenja. I'll give this a try but I shouldn't have thought it'd have been an issue:
I've installed the Production Premium suite to my E drive, which is where it was before. The previous version that was installed with Win7 was uninstalled and deleted (no Adobe folder left on the E drive).
On the C drive, my Windows 10 installation wasn't a "transfer update" but a "fresh, clean update", so all the old previous files are in a Windows.old folder.
I'll try this method and let you know the results. I'm hoping it works!
I followed the instructions but unfortunately this hasn't worked either. The problem still persists after a totally clean reinstallation.