Check that the insecure SMB1 file-sharing protocol is off — via Microsoft Learn

Commandlow riskNeeds adminWindows 11Windows 10

SMBv1 is the old, insecure version of Windows file sharing. Windows 11 doesn't install it by default, but older or upgraded PCs may still have it. One command tells you whether it's there; another removes it.

Restart the computer

The easy way

  1. GUI route: Control Panel → Programs and Features → Turn Windows features on or off → clear SMB 1.0/CIFS File Sharing Support → OK → Restart.

Command

Run in an administrator PowerShell / Terminal window.

Get-WindowsOptionalFeature -Online -FeatureName SMB1Protocol
Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol

Undo

Enable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol
Microsoft strongly advises against SMB1. If an old NAS or printer needs it, update or replace that device instead of turning SMB1 back on. To check without admin rights: Get-SmbServerConfiguration | Format-List EnableSMB1Protocol. On 24H2, SMB signing is required by default, which can also break connections to old NAS boxes. Microsoft says to fix signing on the device, not to change SMB versions.

Sources

Source reviewed
2026-11-02
Link checked
2026-11-02
Tested hands-on
Not by Oddbyte.Me

Oddbyte.Me hasn't tried this on every Windows build, so keep the undo handy.

smb1smbv1securityfile sharingnas

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