Historically, a registration key (often called a product key or serial code) is a specific software licensing mechanism used to prevent piracy. In the context of the original Plants vs. Zombies released on PC (approximately 2009), this key was typically found on a sticker inside the DVD case or on a card included in the physical retail packaging. Upon installing the game, the user was prompted to enter this string of alphanumeric characters to verify that they had purchased a legitimate copy.
Have you found an old CD-ROM in your attic with a working key? Preserve it—you own a piece of gaming history. For everyone else, wishlist PVZ on Steam during the next sale and enjoy 50 levels of zombie-free peace of mind. Plants Vs Zombies Registration Key List
A: No. Steam does not accept external CD keys for PVZ. You must purchase it directly on Steam. Historically, a registration key (often called a product
For the standalone PopCap installer (legacy), the registration system typically required: Order Number: Upon installing the game, the user was prompted
Registration keys (or product keys) were primarily used for the legacy version of the game.