: Windows often flags these launchers as "unsafe" because they aren't digitally signed by a major company. This is normal; select "More info" and then "Run anyway". Missing DLC

Do not use your Steam login credentials anywhere inside IW4x. The client doesn't need them. If a popup asks for your Steam password, you clicked a malicious file.

However, because IW4x is a community-made client and not available on Steam, the installation process can be confusing for newcomers. Unlike modern games where you click "Install" and wait, IW4x requires a specific file structure to function correctly.

Once the game launches, you aren't quite done. To get the best experience, you need to configure a few things.