So, my friend had purchased Call of Duty: Black Ops through steam a while back. He only played 12 hours of it and said I could have it. But, i cant log onto his steam, so i took all the game files and was wondering if there was some way to install the game with the game files. Or should i "back up game files" (option in steam) to my USB stick or PC? Is there anyway to disconnect a game and Steam? Thank you in advance!!