To enable SMB1 on Windows 11, press Windows + R, type optionalfeatures, and press Enter. Expand SMB 1.0/CIFS File Sharing Support, check SMB 1.0/CIFS Client, click OK, and restart your PC. You usually only need the client, which lets your PC connect to old network drives, NAS boxes, printers, and scanners that only support SMB1.
Before you turn it on, know that SMB1 is a decades-old protocol with serious security flaws. It was exploited by the WannaCry and NotPetya ransomware attacks, which is why Microsoft turns it off by default. Enable it only if you have to, and look at the safer alternatives below.
Should you enable SMB1?
- Yes, temporarily: If you need to copy files off an old NAS or connect to an older device that can’t be updated.
- No: If your device supports SMB2 or SMB3. Most devices made in the last decade do, sometimes after a firmware update.
- Never enable the SMB1 server unless you have a very specific reason. Enabling only the client is much less risky.
Method 1: Enable SMB1 with Windows Features
- Press Windows + R, type optionalfeatures, and press Enter. You can also search Start for Turn Windows features on or off.
- Scroll to SMB 1.0/CIFS File Sharing Support and click the + to expand it.
- Check SMB 1.0/CIFS Client.
- Leave SMB 1.0/CIFS Server unchecked unless another device needs to connect to your PC over SMB1.
- Uncheck SMB 1.0/CIFS Automatic Removal if you don’t want Windows to remove the client after a period of not using it.
- Click OK and restart your PC when prompted.
Method 2: Enable SMB1 with PowerShell
- Right-click Start and choose Terminal (Admin).
- To enable only the client, run:
Enable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol-Client -All - Type Y to restart when asked.
To check the status, run Get-WindowsOptionalFeature -Online -FeatureName SMB1Protocol*. Each feature shows Enabled or Disabled.
Connect to the old device
- After restarting, open File Explorer.
- Type \\ followed by the device’s IP address in the address bar, like \\192.168.1.50, and press Enter.
- Enter the device’s username and password if asked.
Older devices may not show up under Network in File Explorer even with SMB1 on, because network discovery works differently. Connecting by IP address is more reliable. You can also right-click This PC and choose Map network drive to keep it connected.
SMB 1.0 isn’t in the list?
Microsoft has been removing SMB1 from newer versions of Windows 11, starting with some editions and builds. If you don’t see SMB 1.0/CIFS File Sharing Support in Windows Features, your installation doesn’t include it. In that case, update the old device or use one of the alternatives below.
Safer alternatives to SMB1
- Update the device’s firmware. Many NAS drives, routers with USB storage, and multifunction printers added SMB2 or SMB3 in later updates. Check the settings page for an SMB version option.
- Set the minimum SMB version on the device to SMB2 if the option exists.
- Use FTP, SFTP, or a web interface to copy files off an old NAS.
- Scan to email or USB instead of scan-to-folder on an older printer.
- Replace the device if it’s past its support life. It likely has other security issues too.
How to turn SMB1 off again
Go back to Windows Features, uncheck SMB 1.0/CIFS File Sharing Support, click OK, and restart. Or run Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol in an admin terminal.
Frequently asked questions
Why did SMB1 turn off by itself?
The SMB 1.0/CIFS Automatic Removal feature removes the SMB1 client if Windows doesn’t detect it being used for a while. Uncheck it in Windows Features to keep SMB1 installed.
Is it safe to enable SMB1 on a home network?
It’s lower risk on a private home network than on a public or business network, but it’s still not recommended. Turn it off when you’re done, and never expose SMB to the internet.
What’s the difference between the SMB1 client and server?
The client lets your PC connect to other devices using SMB1. The server lets other devices connect to your PC using SMB1. Most people only need the client.
Does Windows 11 support SMB2 and SMB3?
Yes. SMB2 and SMB3 are on by default, and they’re faster and much more secure than SMB1.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.