2005 (unused) 2005 (unused) 2005 (unused) 2007–2009, 2013–2015 2009–2023 2015–2020 2020–present
2005 (unused) 2005 (unused) 2005 (unused) 2007–2009, 2013–2015 2009–2023 2015–2020 2020–present

Windows AntiSpyware[]

2005 (unused)[]

Windows AntiSpyware 2005

This feature was firstly seen in Windows Vista (Longhorn) build 5252 as Windows AntiSpyware.

2005 (unused)[]

Windows AntiSpyware

Used in Windows Longhorn builds 5259–5270.

Windows Defender (first era)[]

2005 (unused)[]

In Windows Longhorn build 5270, Windows AntiSpyware was renamed to Windows Defender.

2007–2009, 2013–2015[]


Used in Windows XP, Vista, Windows 7, Windows 8/8.1 and Windows 10 build 1507–1511.

Before Windows 8, Windows Defender was only served as a built-in anti-spyware component, until it became an antivirus software after it was merged with Microsoft Security Essentials in 2012.

Microsoft Security Essentials[]



Used in Windows 7.

With the release of Windows 8, Microsoft Security Essentials was merged with Windows Defender to become a built in antivirus component. However, the Security Essentials app is still supported on older operating systems.

Microsoft Security Essentials on Windows 7 was discontinued in 2023.

Windows Defender (second era) / Microsoft Defender[]


Windows Defender logo

Used in Windows 8.1 (if you install updates) and 10.

Starting with Windows 10 version 1703, Windows Defender was renamed to Windows Defender Security Center and was reformatted into a UWP app, but the antivirus itself is still called Windows Defender.

Starting with Windows 10 version 1803, Windows Defender Security Center was renamed again to Windows Security.

Starting with Windows 10 version 2004, the Windows Defender antivirus was renamed to Microsoft Defender.


Microsoft Defender 2020

This logo was originally designed for Windows 10X, but was only used in Windows 11.