Most store fronts like Steam, Origin, etc. will let you specify where the games are installed. Steam is better about this as you can create a library on any drive and as long as a game is in the library, it'll show up. Or at least, it won't download it from the internet when it finds out the game's files are already there. The other storefronts tend to only let you have one library folder. There are ways around that restriction, but it involves the command line.