Searching for usually leads to a dead end because Forza Horizon 2 was never officially released for PC.
Because there is no official PC version, any site offering a "PC Game DVD" or a direct download for Windows (like the one you mentioned) is . Here is what you should know about the game's current status and availability: Official Availability forza horizon 2 pc game dvdskidrow top
While there is no official version, there are two unofficial ways users attempt to play: Searching for usually leads to a dead end