EPIC FAIL !!
In some cases, the disk 2 of Black Ops II for PC is, in fact, Mass Effect 2.
It seems a joke but, unfortunately, it's 100% real. A lot of people around the Internet are reporting problems with the disk 2 of Call of Duty: Black Ops II. As you can see in the video below they can install the disk 1 of the game, but when they're asked to insert the disk 2 of the game the disk turned out to be a copy of Mass Effect 2...
We hope that the company offers a good solution for all the people with this problem. If you want to play the game now, while you wait for a real solution, you can install the game via Steam and download the missing files from disc 2.
As I said before: EPIC FAIL !!
NEWS SOURCE #1: Black-Ops 2 PC disc2 is apparently Mass Effect 2 major screwup at disc manufacturer (via) GameRanX
NEWS SOURCE #2: Show Thread #3002174 (via) Steam Forums
Our thanks to 'Robe24' for this news item!