Players who bought retail PC copies of Black Ops 2 have popped in the second installation disc to find that it is for Mass Effect 2. Reports on Steam, Reddit, 4chan and the Black Ops 2 forums describe the same problem.
This prevents these players from installing Black Ops 2 with the discs, but each retail copy comes with a Steam key and the entire game can be installed digitally. It will take a while, but it is at least you can play the game without some process that requires the use of US Post Office.
