Available as a standalone antispyware program for Windows XP, Windows Defender shipped with Visa and Windows 7, then it replaced Microsoft Security Essentials as a full antivirus solution since Windows 8. Now, the time has come for it to protect those using the popular Chrome browser, as an extension.
https://www.notebookcheck.net/Windows-Defender-now-available-as-an-extension-for-the-Chrome-browser.299818.0.html