Fly safe, and keep your antivirus happy. Have you found a sketchy "ISO" site? Report it. Have questions about installing the real MSFS? Drop a comment below.
If you are looking for an or FSX to play on an old offline PC or to archive your physical disc, that is a legal gray area. However, even then, you are safer buying used physical discs on eBay or purchasing digital versions from stores like Steam.
If you’ve landed here after searching for “Microsoft Flight Simulator ISO,” you’re likely looking for one of two things: a classic retro version of the simulator you can archive, or (more commonly) a free, downloadable copy of the latest Microsoft Flight Simulator.
If you cannot afford the simulator, save up for a month of Xbox Game Pass. It costs less than a fast-food meal and gives you access to the full, safe, updated simulator.