Key activation instructions:
1. Download (http://steampowered.com/download/SteamInstall.msi) or launch the Steam client.
2. Log in or register a new account on steam.
3. In the lower left corner, click on "+ Add game", and then click on "Activate on Steam" and enter the activation key for the game, which you will receive after payment.
After that, the game will appear in the "Library" section.

MINIMUM:
OS: Windows 7 SP1+ 64bit
Processor: Pentium 4
RAM: 2 GB RAM
Video card: Nvidia® / AMD® with 512 MB memory
DirectX: versions 11
Disk space: 250 MB
Sound card: DirectX compatible

RECOMMENDED:
OS: Windows 7 SP1+ 64bit
Processor: Intel® Core™ 2 Quad / AMD® Phenom
RAM: 4 GB RAM
Video card: Nvidia® / AMD® with 2GB memory
DirectX: versions 12
Disk space: 250 MB
Sound card: DirectX compatible