Problem moving to new machine

When I installed MSFS2020 on my computer it would not run because the machine was not up to it. I have since bought a new machine and re-installed the 10 DVDs, but when I try to ‘Redeem a code’ it says that the code has already been used. I hoped that I would be abe to download it again from My Library, but the library is empty - no sign of MSFS. Can anybody help me with this issue?

You need to sign in using same username you used during purchase (original code redeem). Microsoft Store saves all purchases. It should be there

Im having same problem cant use the redeem code again and its not stored any where or fsx 2020

Not sure, but you might also need to add your new PC to your microsoft account.