How do I activate this on Steam?

[Baroness Snark]

I picked up the retail DVD used for only $3 last week. Game runs fine (although I had to patch it to the latest version because it kept crashing during the loading screen for the first level), but I am unable to add it to my Steam account.

Do I have to install the multiplayer version or use a CD key? There's no CD key when you install the game, and the version I bought does not have a manual with any kind of Steam activation key. I tried googling for a CD or Steam activation key, but no dice.

Thanks.

[5M0k1N]

if the game has no key anywhere then youprobably cant. even if it did, sometimes you still cant, depends on the game.

[Baroness Snark]

Originally posted by 5M0k1N:

if the game has no key anywhere then youprobably cant. even if it did, sometimes you still cant, depends on the game.

The DVD does have a Steam installer already on it, for what it's worth.

I might end up just buying the game directly off Steam instead if I can't activate it. I also bought Bioshock used and cannot activate it either.

[Nova]

To activate game on Steam you need an activation code - try to ask your vendor. If there is no such key you can still add game to the library: https://support.steampowered.com/kb_article.php?ref=2219-YDJV-5557&l=english