How to activate 12 Months Xbox Live Gold Membership Card?
Visit this address: http://www.xbox.com/redeemcode
Sign in with your Microsoft account credentials
Enter the 25-character code and Confirm

You can find additional support for your Xbox Live account here: https://support.xbox.com/contact-us

This product is a brand new and unused Xbox Live 12 Month Gold subscription code.  It will grant you to 12 months access to Xbox Live Gold.