Windows 10 Enterprise E5 includes Windows 10 Enterprise E3 plus Windows Defender Advanced Thread Protection (ATP). Windows Defender (ATP) enables enterprise customers to detect, investigate, and respond to advanced attacks and zero days on their networks—for up to six months, in a single timeline. It is built-in, cloud powered, and leverages the Microsoft Intelligence Security Graph to integrate detection and exploration with Office 365 ATP*. *some separate subscriptions may be required. Compare Windows 10 Enterprise E3 vs E5.