|2005 (unused)||2005 (unused)||2006–2009, 2013–2015||2009–2013||2015–2020||2020–present|
This feature was fistly seen in Windows Vista Beta Build 5252, it was originally called Windows AntiSpyware.
Windows Defender (first era)
In Windows Vista Beta Build 5270 Windows AntiSpyware was renamed to Windows Defender.
The logo was used in Windows XP, Vista, Windows 7, Windows 8/8.1 and Windows 10 Versions 1507 and 1511.
Before Windows 8, Windows Defender was only served as a built-in antispyware component, until it became a built-in antivirus software after it was merged with Microsoft Security Essentials in 2012.
Microsoft Security Essentials
The launch of Windows 7 introduced a new antivirus software called Microsoft Security Essentials. The icon resembles a medieval castle with a blue flag sticking out.
With the release of Windows 8, Microsoft Security Essentials was merged with the Windows Defender to become a built in antivirus component but they will still supporting Microsoft Security Essentials on older OS.
Microsoft Security Essentials on Windows 7 will be discontinued by 2023.
Windows Defender (second era) / Microsoft Defender
This logo is used on Windows 10, starting with Version 1607. This logo was also shown on Windows 8.1 via an update from 2016.
Starting Windows 10 Version 2004, Windows Defender was renamed to Microsoft Defender.
This logo was originally designed for Windows 10X, but was only used in Windows 11.
Microsoft Windows apps
1 Spun off into a Microsoft Store app