Even if you had a legitimate, unused activation code from an old DVD copy, the activation servers it was meant to talk to are no longer there. You would be unable to complete the installation process. This makes any unused activation code worthless.
Since you can't just buy a code and hit "Activate," players usually follow one of these paths: battle los angeles pc activation code
Before attempting third-party fixes, check if the manual unlock portal works for your specific edition. Even if you had a legitimate, unused activation