FS2020 is located on C:
Don’t format it if you want to keep FS2020 working.
FS2020 on D: is okay.
You can format C: and then install Win 10 on it. Create new Win 10 USB.
Then go to the MS Store and have it Install FS2020 again.
It will install FS2020 on your C: drive.
MS Store will see you FS2020 data on your D: drive and will not
download it again.