Downloads are conveniently located on the Descent: Underground tab of your Client Area.
Steam Keys are conveniently located on the Descent: Underground tab of your Client Area.
To retrieve a Steam Key the following must be true:
- You must be logged in to your Descendent Studios Account
Your Account must own a copy of Descent: Underground obtained through our Store or Kickstarter
- If you backed on Kickstarter, please be sure that you have Linked your Kickstarter Pledge to your Descendent Studios Account
- You must have redeemed your copy of the game to your account
Please follow these instructions to activate your Steam Key on your Steam Account:
- Launch the Steam client software and log into your Steam account.
- Click the Games Menu
- Choose Activate a Product on Steam...
- Follow the onscreen instructions to complete the process.
Paraphrased from https://support.steampowered.com/kb_article.php?ref=5414-TFBN-1352