If you are trying to install from an old disc on Windows 10 or 11, you may need to run the installer in Compatibility Mode (Windows XP SP3) and as an Administrator

Once the key is accepted, you can create your soldier and join a server.

Given that EA no longer sells the game, your options are limited. Here is a realistic, step-by-step approach to finding a key that works.

Official EA Servers are dead. The community lives on Battlefield 2142 Reclamation (or similar revival projects). You must download their client installer. This is not a crack; it is a modified launcher that redirects your connection to community servers.