Windows 11 improves security by cutting SMB1 from Insider Builds
Microsoft continues to move away from the insecure SMB1 protocol.
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 users with technical expertise to help their friends and family that experience problems.
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Sean Endicott is a News Writer at Windows Central, where he covers Windows 11, Surface hardware, Microsoft 365, AI, apps, and the broader PC ecosystem. Since joining the site in 2017, he has written well over a thousand articles across the Microsoft landscape, covering breaking news, analysis, and feature reporting.
He writes Windows Wrap, a weekly column covering the biggest stories in Windows and the PC industry, and what they mean for the platform going forward.
Before joining Windows Central full-time, Sean worked in journalism and media production after earning a First Class degree in Broadcast Journalism from Nottingham Trent University. Outside of tech, he is an award-winning American football coach based in Nottingham, England, and was named BAFCA Youth Coach of the Year in 2024.
