The most successful and active project for this is , an open-source Xbox 360 emulator. Over the last few years, the developers of Xenia have made massive breakthroughs, allowing the Xbox 360 version of Forza Horizon 2 to run at playable framerates on modern computer hardware. System Requirements for Emulation
If you want the "Horizon" experience on your PC without the risks of unofficial downloads, these titles are natively supported: forza horizon 2 free download pc new