nightwing bundle pack not working

[VikingHeathen]

ok so i paid for the night wing bundle and i have it in my CD key shortcut but for some reason thats beyond me is that the game doesnt see the code. Why can i see it but not play it?

[Pallando]

Well, for GFWL games, you need to install DLC from Games For Windows Marketplace.
You don't get the DLC through Steam, just the CD key.

However, GFWL has been removed from of Arkham Asylum GOTY and Arkham City GOTY: these games are now Steamworks.
Moreover, everyone who owns the standard edition on Steam got a free upgrade to the GOTY edition (which contains all the DLC).
Read here:
http://steamcommunity.com/games/200260/announcements/detail/1909817119598626547

You'll notice that they say that you'll lose your savegames.
But that's not entirely true. You need to patch them. There's a how-to on the Arkham City GOTY forum. I've also made a tool to automatically patch saves.

Check here:
http://steamcommunity.com/sharedfiles/filedetails/?id=188027765#164417

I've recently updated the software in order to make the process easier, but there were some oversights on my part... But this should be fixed by now. And the tool should now allow you to patch your saves in 1 click.

However, if you have problems, tell me. There's also a link in the guide introduction towards the manual way of editing saves.