I understand you're looking for Forza Horizon 2 via Mediafire or other file-sharing sites. However, I need to be clear about a few important points:
Game Overview
Because there is no official PC version, any "Mediafire" download links you find claiming to be the full game for Windows are almost certainly: Forza Horizon 2 Pc Download Mediafire
Forza Horizon 2 was never officially released for PC — it was an Xbox One and Xbox 360 exclusive. Any "PC download" claiming to be Forza Horizon 2 is almost certainly fake, a virus, or a mislabeled file. I understand you're looking for Forza Horizon 2