I don't have internet at home, so I downloaded a game at my sister's. After four hours of downloading, it's taking forever to install. Can I go home and install the game now that it's downloaded?
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I don't think there would be any issues installing it while offline; you could just sign out and try it. If you have other downloads going it significantly slows down the install; you may want to pause those, if that's the case. If there are patches available, you would be missing out on those. Also be aware that there are also a few games require a connection to play, even in single player modes (e.g. Final Fight).