Windows 10 Can’t Connect to File Share Because It’s Not Secure: Reaching an Old NAS or Network Drive

You try to open a folder on an older network storage box, media player, or router with a USB drive attached. Windows refuses with: “You can’t connect to the file share because it’s not secure. This share requires the obsolete SMB1 protocol, which is unsafe and could expose your system to attack.” When Windows 10 can’t connect to file share because it’s not secure, the device is using a file sharing language Windows no longer speaks by default.

SMB is the protocol Windows uses to share files over a network. Version 1, called SMB1, is more than 30 years old and was abused by major ransomware outbreaks such as WannaCry. Microsoft therefore removed or disabled SMB1 in newer Windows 10 installations.

Older NAS boxes and routers that only support SMB1 now look unreachable, even though they still work.

The safest fix is to make the device use a newer SMB version rather than turning SMB1 back on.

Why This Happens

The connection fails for these reasons:

• The device supports only SMB1.
• SMB1 Client is not installed or is disabled on Windows 10.
• The device’s firmware is outdated and has a newer SMB option turned off.
• Guest access to the share is blocked by Windows security rules.

A related message about “unauthenticated guest access” appears when the link slot share uses no password; that is a separate security block.

Start With These Basic Checks

Upgrade the device side first.

1. Sign in to the NAS or router’s admin page in a browser.
2. Look for file sharing, SMB, or Windows sharing settings.
3. Set the minimum SMB version to SMB2 or higher, or turn on SMB2/SMB3 support.
4. Update the device’s firmware from the manufacturer’s website.
5. Create a user name and password for the share instead of using guest access.

Then try opening \\DeviceName or \\IPAddress again in File Explorer.

Going a Step Further

Use SMB1 only as a temporary last resort.

1. Open Control Panel > Programs > Turn Windows features on or off.
2. Expand “SMB 1.0/CIFS File Sharing Support” and tick only “SMB 1.0/CIFS Client.”
3. Restart the PC and connect to the device.
4. Copy your files to a newer storage device.
5. Turn SMB1 off again when you are finished.

Leave “SMB 1.0/CIFS Server” unticked, since your PC does not need to offer SMB1 to others.

A Word of Caution

SMB1 has known flaws that malware has exploited across whole networks. Plan to replace devices that cannot support SMB2 or newer, and never enable SMB1 on PCs that connect to public networks.

Final Thoughts

This message means the device needs the outdated SMB1 protocol. Enable SMB2 or newer on the device, update its firmware, and use the SMB1 client only briefly to move data off old hardware.