Activating an XBOX Live key is really simple, just follow those steps:
1.Log into your XBOX account.
2.Click on your avatar that is visible in the top right corner of the screen and click on Redeem code.
3.Now click Redeem that is in the center of the page.
4.Write the code you have received and click Redeem.
5.Confirm the activation and click Confirm.
The key is not working
If you have activated the key according to the guide but the code appears not to work, please check what type of error message you receive and depending on it follow the appropriate instructions: