If you absolutely want the original 2007 executable for modding or nostalgia, your only safe legal route is a used physical DVD copy with an unused CD key.
Here’s an informative write-up for someone searching how to download Call of Duty: Modern Warfare (the original 2007 game) on PC. If you’re looking to download the 2007 classic Call of Duty 4: Modern Warfare (often referred to as the first Modern Warfare ), it’s important to distinguish it from the 2019 reboot of the same name. This guide covers the original game that introduced iconic characters like Captain Price, Gaz, and Soap MacTavish.
Stay safe, and enjoy one of the most influential first-person shooters ever made.