Transfer Microsoft flight simulation from one PC to another?

I have brought microsoft flight simulator from my notebook to my PC and the desktop screen shows that I have it and when I click on the symbol, Flight Simulator starts but after a while it says "Installation manager" and I'm asked to reload the 96Gb file what can I do about it because I already have the file.

You have to copy the files into the correct directory - you can specify this during the installation.