1. Install Steam that is in the folder "SteamInstall.exe"
2. Creat a new account on Steam, don't use your existing account if you have it
3. Go to
http://store.steampowered.com/app/18800/ and install the Demo of Zero Gear
4. Go to the installation folder of Zero Gear, under Steam, and go to the subfolder called "Server" (C: \Program Files\Steam\steamapps\common\zero gear\Server)
5. Delete all the content of the "Server" folder
6. Copy all the file of your Call of Duty Modern Warfare 2 and paste it in the "Server" folder (C: \Program Files\Steam\steamapps\common\zero gear\Server)
7. Go to "C: \Programmi\Steam\steamapps\common\zero gear\Server\zone" and rename your language folder to "english" (if your game is english jump this step)
8. Go in the folder "Customed Version\Multiplayer Online" (the files you have downloaded) and copy all his content and paste it in "C: \Program Files\Steam\steamapps\common" overwriting the existing files
9. Open Steam, and go to "My Games" where you can find your previously installed Zero Gear game
10. Right click on the Zero Gear game and select "Property"
11. Go to the tab called "Updates" and disable the updates by selecting "Do not update this game automatically"
12. Save clicking "Close"
13. Open Steam, and go to "Friends" window, and turn off your status (Go to "Status" tab and select "Offline")
14. Go to "Steam" window and go to "File -> Settings" and go to the Friends Tab. Deselect the first option (Sign-in to Friends when run Steam)
15. Run COD MW2 from the Steam folder. Double click on C:\Program Files\Steam\steamapps\common\zero gear\Server\iw4mp.exe