Developed by a team of experienced modders from the Paradox forum, Darkest Hour is a stand-alone Hearts of Iron game. The game features a mixture of short and in-depth campaigns set across the darkest chapters of the 20th century. Play from the outbreak of the Great War up until the onset of the Cold War.Go to: http://store.steampowered.com/ and download STEAM client
Click “Install Steam” (from the upper right corner)
Install and start application, login with your Account name and Password (create one if you don’t have).
Please follow these instructions to activate a new retail purchase on Steam:
Launch Steam and log into your Steam account.
Click the Games Menu.
Choose Activate a Product on Steam…
Follow the onscreen instructions to complete the process.
After successful code verification go to the “MY GAMES” tab and start downloading.