To combat piracy, EA used DRM (Digital Rights Management) combined with a mandatory online activation. The serial number (also called a CD key, product code, or license key) typically looked like this:
Introduction If you are searching for the term "Serial Number Nfs Shift 2 Unleashed," you have likely just installed a shiny copy of Need for Speed: Shift 2 Unleashed —either from an old DVD-ROM, a second-hand disc, or a long-forgotten digital backup. Upon launching the game, you were greeted by a stark, grey dialog box demanding a 20-character alphanumeric code. Serial Number Nfs Shift 2 Unleashed
XXXX-XXXX-XXXX-XXXX-XXXX