Thanks, Akki and Mathijs for your replies! I'm still a little unsure because the Gamestar says that you shouldn't install MSFS on the hard drive on which the operating system is located. So far i have installed all flight simulators (FSX, P3D, X-Plane) on the same hard drive with the operating system, only in a separate directory. Is that different with MSFS? I understood that it is possible to install MSFS on a separate harddrive. But is it also necessary or recommended?