Forza Horizon 1 never received an official PC release. Any "PC repack" or direct MediaFire download you find is almost certainly a pirated console ISO bundled with an emulator or, worse, malware. The only legitimate and reliable way to play the original Forza Horizon on PC is via Xbox 360 emulation. PC Performance Review (via Emulation)
Playing Forza Horizon 1 on PC using the Xenia Emulator (specifically the Canary build) is the current "gold standard" for the best experience. Forza Horizon REMASTERED on Xenia Emulator forza+horizon+1+pc+repack+download+hot+mediafire
Here is text written in the style of a typical game download/repack site post, optimized for the keywords you provided. Forza Horizon 1 never received an official PC release
If you have a limited internet connection or low disk space, this repack is the best solution. If you have a limited internet connection or
Repack versions usually come with a crack included for activation.