Skip to main content

Windows 11 improves security by cutting SMB1 from Insider Builds

Surface Laptop Studio Hero
Surface Laptop Studio Hero (Image credit: Daniel Rubino / Windows Central)

What you need to know

  • Insider builds of Windows 11 Home no longer ship with SMB1 installed.
  • SMB1 is an insecure security protocol that is 30 years old.
  • Microsoft will also remove SMB1 binaries from Windows and Windows Server with a future release.

Windows 10 and Windows Server started shipping without Server Message Block version 1 (SMB1) installed by default back in 2017. Now, Windows 11 appears set to follow suit. As of this week, Insider builds of Windows 11 Home will no longer have SMB1 installed. As a result of the change, there are now no Insider builds of Windows 11 that have SMB1 enabled by default.

SMB1 is a file-sharing protocol that has been around for 30 years. Some legacy pieces of software and older NAS still rely on it, but the protocol is not secure. There are newer versions of Server Message Block, SMB2 and SMB3, that are more secure.

The infamous WannaCry and Petya ransomware attacks both took advantage of a flaw discovered in SMB1. Microsoft has moved away from SMB1 for quite some time, so disabling it by default is a natural step for Windows.

The change will not affect PCs that already used SMB1 and received in-place upgrades. Admins also still have the option to reinstall the protocol.

Microsoft will remove SMB1 binaries in future releases of Windows as well. Windows and Windows Server won't have the drivers and DLLs for SMB1. An out-of-band unsupported install package will be available for organizations that require SMB1 to connect to devices such as older factory machinery, medical equipment, and NAS.

The change in behavior won't affect people running newer PCs. Those on certain older systems will have an issue connecting to a networked hard drive. Microsoft's Ned Pyle invites (opens in new tab) users with technical expertise to help their friends and family that experience problems.

Sean Endicott
News Writer and apps editor

Sean Endicott brings nearly a decade of experience covering Microsoft and Windows news to Windows Central. He joined our team in 2017 as an app reviewer and now heads up our day-to-day news coverage. If you have a news tip or an app to review, hit him up at sean.endicott@futurenet.com (opens in new tab).