Hey, I decided to buy the diablo II battle chest as a birthday gift for a friend so we could play together on battle.net, however I had misplaced my Expansion CD somewhere, but still have the case with the CD key. I didn't think it'd be an issue to use the CD I bought for him to install the game, and use my own CD key with it, but when I popped in the disk, I discovered there's a newer version of the installer, and the newer CD keys are longer than mine, it wont accept my old 16 digit CD key. Is there anything I can do?

Sweet, that works just fine, but now we have a larger issue.

I'm not very good with computers, neither of us are, We're getting the "Problem authenticating" error on his downloader and it keeps closing. Hes running windows 7, so I'm guessing thats alot of the problem.

I've searched around and the most common suggestion seems to be running as administrator, but I just have no idea how to do that using windows 7.

Right-click the file and select "Run as Administrator".