IW5 (Modern Warfare 3) — Plutonium

What you’ll need

• Steam installed and logged in.
• Modern Warfare 3 base files (free via the Dedicated Server package if you don’t own the game).

We recommend buying MW3 if you enjoy it—you’ll support the developers and avoid missing assets.

Get the MW3 base files

Pick one of the methods below to install the “Call of Duty: Modern Warfare 3 – Dedicated Server” in Steam.

Method 1 — Quick link

1. Click: Install MW3 Dedicated Server in Steam
2. Accept the Steam prompt to begin installing.

Method 2 — Through the Steam UI

1. In Steam, open Library and set the filter dropdown to “Tools”.
2. Find “Call of Duty: Modern Warfare 3 – Dedicated Server”.
3. Open the cog menu → Properties → Language, and set it to English. This is required so all files install correctly.
4. Click Install → Next → Finish and let it download. Track progress from Steam’s Downloads view.

Default path on Windows

C:\Program Files (x86)\Steam\steamapps\common\Call of Duty Modern Warfare 3

Set up IW5 in the Plutonium Launcher

1. Launch the Plutonium Launcher. If you need it: plutonium.exe
2. Select Modern Warfare 3 and click Setup.
3. When prompted, choose the MW3 folder shown above (the folder that contains the game files).
4. Confirm the path and let the launcher verify and prepare the game.
5. Click Play in the launcher to start IW5.

Notes

• To reselect the folder later, click Game Settings next to the Play button.
• Make sure you point to the actual MW3 directory—not a parent “Games” folder or Documents.