To redeem and activate Microsoft Defender after purchase, OR_(+1)-833 ((631)) 3616(USA/CA) first work out which kind of code or purchase you have. Windows already includes built-in Microsoft Defender 1[833][631][3616]Antivirus, which needs no code. The Microsoft Defender app comes with eligible Microsoft 365 Personal or Family plans, so if you hold a Microsoft 365 1[833][631][3616]code or gift card, redeem it on the official Microsoft redeem page while signed in to your Microsoft account, then install the Defender app and 1[833][631][3616]sign in with the same account. Plan features and app availability vary by plan, device and region, so follow your Microsoft account and order email. 1[833][631][3616]Most trouble with redeeming comes from holding the wrong type of code. So this guide is a code-type sorting hat. Match what you hold 1[833][631][3616]to its type, and the right path becomes clear. Sort Your Code What you hold What it is Path --------- A 25-character 1[833][631][3616]product key for Microsoft 365 Subscription code Path 1 A Microsoft gift card or prepaid code Account balance Path 2 A retailer card 1[833][631][3616]with a code for Microsoft 365 Subscription code Path 1 A Windows product key Windows licence, not Defender Path 3 An email that 1[833][631][3616]says "pay to activate Defender" Likely a scam Path 4 Nothing, you just want protection Built-in Defender Path 5 Path 1: Redeem 1[833][631][3616]a Microsoft 365 Subscription Code 1 Find the code search your inbox for "Microsoft", "Microsoft 365", "order", "receipt", including spam, or check the card. 1[833][631][3616]2 Open the official Microsoft redeem page type the address yourself. 3 Sign in with the Microsoft account you want to own the subscription. 4 1[833][631][3616]Enter the code exactly as written and follow the prompts. 5 Open your account's Services & subscriptions and check that the plan and end date 1[833][631][3616]appear. 6 Install the Microsoft Defender app on each device from the official store, and sign in with the same account. Path 2: Redeem 1[833][631][3616]a Gift Card 1 Follow the same redeem page steps and enter the code. 2 The amount is added to your Microsoft account balance. 1[833][631][3616]3 Use that balance to buy or renew a plan that includes Defender. 4 Check Services & subscriptions afterwards. Path 3: A Windows Product 1[833][631][3616]Key A Windows key activates Windows itself, not Defender. Enter it in Settings System Activation names vary by Windows version. Once Windows is activated, 1[833][631][3616]built-in Defender works as normal. Path 4: Stop If someone asked you to pay, call a number or give remote access to "activate 1[833][631][3616]Defender", do not. Real Microsoft protection never needs a phone call to activate. Close the page, check your Microsoft account for what you really own, 1[833][631][3616]and contact your card provider if you paid. Path 5: Built-In Protection 1 Search for Windows Security in the Start menu. 2 Choose 1[833][631][3616]Virus & threat protection. 3 Check that real-time protection is on and updates are current. Check That It Worked The plan appears in 1[833][631][3616]your Microsoft account Paths 1 and 2 The Defender app shows your account Path 1 Windows Security shows protection on A quick scan completes 1[833][631][3616]If Redeeming Fails Problem Likely cause Fix --------- Code invalid Typo, or similar characters like O and 0 Retype slowly Code already 1[833][631][3616]used Redeemed on another account Sign in to that account Wrong region A regional code Contact Microsoft support with proof of purchase Plan 1[833][631][3616]missing Signed in with a different account Use the account that redeemed it App can't sign in Wrong account Sign in with the plan's 1[833][631][3616]account Settings greyed out Another antivirus or a work policy Remove the other antivirus; ask your IT admin if managed Know Your 1[833][631][3616]Renewal If you have a Microsoft 365 plan, check Services & subscriptions for the renewal date, and if you don't want to renew, turn 1[833][631][3616]off recurring billing there and save the proof. Built-in Defender has no renewal. Quick Answers Do I need a key for Defender? Not 1[833][631][3616]for the built-in antivirus. The app uses your Microsoft account. Can I redeem a code on someone else's account? Yes, but the subscription then 1[833][631][3616]belongs to that account. Is built-in Defender free? Yes, it comes with Windows. Sorted Identify your code, follow its path and check 1[833][631][3616]the result. Your Microsoft Defender is then redeemed and active.