Redeeming a Microsoft Store game code is simple to do using the in-built Microsoft Store on Windows 10 PC.
- Microsoft Store App
Load the Microsoft Store app on your Windows 10 PC, make sure you're signed in to the Microsoft account you wish to link the product to and then click the three little dots in the top right to open the drop down menu, then click Redeem a code.
- Enter Your Code
Type or paste in your 25 digit key/code and click Next
- Confirm Redemption
It will show you the product you're going to get by redeeming the code when you click Confirm - Once you click confirm the product is permanently linked to your Microsoft account and there are no refunds.
Now the game is linked to your account you need to install it. Click the three little dots again, in the drop down menu click My Library. In the left hand column, click Ready to install, your game should be listed with an Install link to click.
Notice: If you had a trial/demo version of a game already installed, you should un-install that before installing from your Library otherwise it can cause an error saying you only have a trial/demo version despite redeeming a code for the full game.