Where Microsoft Defender fits
Explore it when you want to manage security through a Microsoft account.
Check before you choose
The subscription app and Windows Security's built-in antivirus are different offerings; check which one you need.
Find the right edition
Start with the destination for your device or the publisher's website. Use the current requirements and terms there to confirm the edition you need.
Compare the workflow
Start by checking the protection already running on your device. A permanent security suite, a portable scanner and a browser-cleanup utility are different interventions; installing several at once can complicate diagnosis.