thanks for the information.
I did it, but another problem started.
I moved the Modeller9v7 folder to Desktop
No, don't do that! That will (as you discovered) break Modeller. (In
fact, this is the case for most Windows programs - don't move them after
you install them.) Make a new directory for your own scripts, but leave
Modeller (and Python) where they are. If you want to run the Modeller
examples, copy (not move) the examples directory (not the whole Modeller
directory) to a new location.