Microsoft Deprecates SmartScreen in Internet Explorer and IE Mode on Windows 11

Microsoft has officially deprecated Defender SmartScreen in Internet Explorer (IE) and IE Mode on Windows 11. The company confirmed this in a support document published under KB5071357.

The change detailed by Microsoft takes effect with the latest Windows updates. While SmartScreen remains active in Microsoft Edge, Windows Shell, and other supported areas, it no longer functions inside IE or IE Mode sessions on Windows 11. On older Windows versions, however, SmartScreen will continue to work as usual.

SmartScreen was originally designed to block phishing sites, detect unsafe downloads, and scan files tagged with Mark-of-the-Web (MotW). But since Internet Explorer is no longer a standalone browser on Windows 11. And IE Mode exists solely for enterprise-managed, intranet sites. Microsoft says the feature had become redundant, one of the reasons why it’s being deprecated.

The company explained that legacy SmartScreen binaries were also removed as part of Windows’ ongoing security modernization. Retaining the feature inside IE Mode would have led to instability and inconsistent behavior, according to Microsoft.

That said, files downloaded via IE Mode will continue to carry MotW tags. In other words, they’ll be checked by SmartScreen when opened in Windows Explorer. Meanwhile, Microsoft Defender and Defender for Endpoint continue to guard against malware at the system level.

If you’re an admin, Microsoft recommends confirming that SmartScreen is disabled in IE Mode settings and that only trusted enterprise sites are included in the mode’s configuration list.