Microsoft officially "delisted" Forza Horizon 1 years ago [1, 6]. This means it is no longer available for purchase on the Microsoft Store, and they no longer generate or sell new digital licenses for it [6]. 4. Only Remaining Legit Option: Xbox 360 Physical Disc
If you have an Xbox 360 or a modern Xbox console (which is backwards compatible), the only 100% legitimate way to play is by buying a from marketplaces like eBay or local game shops [1, 6]. Forza Horizon 1 Pc Registration Code
Here is the technical reality: Forza Horizon 1 on PC is protected by DRM. If you find a "code" online and try to use it, one of three things will usually happen: Microsoft officially "delisted" Forza Horizon 1 years ago
If you've purchased a physical copy of the game, the registration code can be found on the game's packaging or on a separate card. Only Remaining Legit Option: Xbox 360 Physical Disc