Whether you are using a standard Steam installation or a portable version, installing a save game is relatively simple. The key is finding the correct directory.
While Fernbus Simulator itself is not a portable application (it requires installation via Steam or other platforms), your is portable. Because the game stores progress in a specific folder on your hard drive, you can copy this folder to a USB drive and paste it onto another computer. This allows you to continue your 100% progress on a laptop, a friend's PC, or a backup machine. fernbus+simulator+save+game+100+portable
Sometimes in: %LocalAppData%\Fernbus\Saved\SaveGames\ (even for portable versions) Whether you are using a standard Steam installation