THE DOWNLOAD METHODS AND STEPS:
a) Download steam: http://store.steampowered.com/about/?l=english
On the left you are going to find the button: "Install Steam Now". Just click and a pop-up will appear, where you can download Steam.
b) Install Steam: Double-click on the downloaded file: SteamInstall.msi
Follow the instructions during installation. Important: choose the language steam will be available to you (just select the field in front of your country language selection). Steam will be installed...
c) Setup your Steam Account
After Steam installation a new window opens: "Open new account" or "log into existing account".
If you don´t have a Steam account, please click on "open new account".
Read the terms & conditions, accept bei clicking "I agree". Registering a Steam-account is for free!
Follow further instructions (setup account name and password).
After setting up your account name and password and providing a valid email address, your Steam-account has been opened. The program can be found in the tray-icon and is normally located on the right bottom of the task or symbol bar.
d) Register the game at Steam
The Steam window shows several tabs on top, one of the tab shows "Games".
Please click on "my game" and two new buttons appear on the buttom: "add a non-steam game" and "Register a product at Steam"...
Please keep your CD-Key available and click at "Register a product at Steam" and follow the instructions.
e) Download the game
If your key has been entered successful, the game will be listed below "Games" with the status "install". Klick on the game and the Download will start immediately. The game will be installed and it will start automatically.