If you own the original DVD set, you can install the files, but the "Play" button will usually trigger an Origin prompt. To bypass this: Run the setup.exe from the DVD.
That being said, here are the general steps to download and install Medal of Honor Warfighter from a third-party website: how to install medal of honor warfighter without origin
Electronic Arts originally tied Medal of Honor: Warfighter directly to Origin for digital rights management (DRM) and multiplayer matchmaking. Today, Origin has been officially retired and replaced by the EA App. However, this app is notorious for high CPU usage, forced updates, and login errors that prevent older games from launching. To play without it, you must bypass the standard DRM validation. If you own the original DVD set, you