[Sisk0]

Well that is really odd! The CD Key is linked to your steam account, so if you install steam on a different computer and use your steam login, it should play. I mean, when I bought a new PC I really didn't uninstall steam on my previous PC, also when I format the PC I also don't uninstall steam, I just reinstall anywhere on any PC and it works, as long as it's my steam account.

Perhaps you can do the following: install steam. Go to 'my games'. You will see all the games connected to your steam account. You will also see that some of them are not installed. Now double click and choose to install the game through steam. Now you don't need the CD, and yes, it may take some time to download, but it might work!