For those of you who purchased the physical boxed set of MS Flight Simulator 2020 you were probably surprised (and annoyed) that you have to have DVD Disk 1 inserted into your DVD drive before you play the game (every time you play).
I got round this by creating an ISO image of DVD Disk 1 and have that 'mounted' as a virtual DVD drive. This means I can disconnect my physical DVD drive (which is an external/portable one) and still play the game. It detects the virtual DVD drive with the 'disk inserted'.
A PDF guide is attached.
I accept no liability whatsoever...