Before you can play, you'll need to download the Windows client for Microsoft Flight. Also, note that you'll need a decent games-spec graphics card in your PC, so check the requirements on the web site carefully. It also requires Windows 7.
Plus, be aware that the download is some 1,500 MB (1.5 GB)
If you're still interested, head to https://microsoftfli...com/en-US/home/