Upgrading SSD m.2 MSFS Drive from 1TB to 2TB?

Right…

I had to remove my MSFS M.2 drive from my system as I only had two M.2 sockets & needed to clone my C: system drive to a larger m.2 Drive. I cloned the drive succesfully. After the process & re-inserted my MSFS m.2 drive but now despite all the files bring present on my MSFS drive the program thinks it’s not installed yet all the files are on the drive. Same applies to some Microsoft Forza Horizon 4 & Sea Of Thieves. How can I get my PC to realise that these games are installed without having to Download everthing again? Due to the two latter programs in a similar state, which are not on the MSFS drive I am beginning to wonder if Microsoft copy protection is at work here. All I want to do is repair the installs NOT re-download these big programs as my Internet speed is only 40meg! (It’ll take ages!!!)