Fixing Windows 11 Access to Windows XP Shares: Enabling SMB 1.0

Resolving Incompatibility Between Windows 11 and Legacy Windows XP File Shares

In our office, we continue to utilize an extremely outdated laptop (equipped with a Pentium III and 256MB RAM running Windows XP) as a dedicated print and file server. Surprisingly, it has served its purpose well over the years. Other Windows devices, including those running Windows 7 and even older versions of Windows 10, had no trouble accessing shared folders and printers hosted on this XP machine.

However, one particular PC running Windows 11 was persistently unable to connect to the XP machine's shared resources. This resulted in a tedious workaround—uploading files to the cloud and printing them from a secondary device running Windows 7.

Diagnosis

After applying the latest Windows 11 updates, an attempt to reconnect to the XP machine resulted in a specific error message that finally shed light on the issue:

Figure 1. SMB 1.0 error message shown when attempting to access Windows XP share from Windows 11.

As suspected, SMB 1.0 was disabled. This protocol is essential for legacy systems like Windows XP to communicate over a local network. While I had disabled SMB 1.0 months earlier as a precaution against ransomware vulnerabilities, I had forgotten to re-enable it for this particular use case.

Solution: Enabling SMB 1.0 in Windows 11

To restore compatibility, I enabled SMB 1.0/CIFS support in Windows 11. Here's how:

1. Open Control Panel → Programs → Turn Windows features on or off.

Figure 2. Windows Features dialog — scroll to locate "SMB 1.0/CIFS File Sharing Support"

2. Scroll down and enable SMB 1.0/CIFS File Sharing Support. In my case, I only enabled SMB 1.0 Client and Automatic Removal, excluding the server component.

Figure 3. Only "SMB 1.0/CIFS Client" and "Automatic Removal" checked — the server option left disabled

3. Reboot your PC to apply the changes.

Result

Following the reboot, the Windows 11 system was able to access both file shares and the printer hosted on the XP machine without any issues. It now functions seamlessly alongside other devices in the local network.

⚠️ Important Security Warning

Enabling SMB 1.0 exposes your system to known vulnerabilities, as this protocol is outdated and susceptible to ransomware attacks such as WannaCry. While it may be necessary for legacy compatibility, it should only be enabled in isolated networks where security risks are mitigated.

Please proceed at your own risk. The author bears no responsibility for any potential damages.