Will Windows Defender Antivirus keep working and receiving updates on Windows 10 after October 2025?

We're confident it will: Windows Defender Antivirus is still working and receiving all updates on Windows 10 versions that have long gone out of support, such as 1809 or 2004.

We expect Windows Defender Antivirus will remain fully operational on Windows 10 22H2 at least as long as this Windows 10 version keeps receiving Extended Security Updates (October 2028), but likely longer as some Windows 10 versions like 1809 (E) (LTS) or 21H2 IoT (LTS) remain supported until 2029 and 2032, respectively.