Windows 10 Build 2004 / 20H1 – SMBv1 network drives not connecting

The newest builds and updates can possibly break some Windows 10 network connections. Saw this specifically in a situation with a SMBv1 drive that was connected via FQDN per GPO.

Windows was not able to connect to the drive, looking at NET USE all you saw was reconnecting.

Connecting to the same share via HOSTNAME and/or IP worked just fine, as well as engaging the UNC path.

The solution to this eventually is a simple registry adjustment, that has to be done in the user-profile HKCU area, so no advanced rights are needed.

Steps:

  1. open REGEDIT
  2. go to HKCU\Network
  3. select the key with the drive-letter you have issues with
  4. add a new REG-DWORD
    1. PROVIDERFLAGS
    2. Decimal 1 or DWORD 00000001
  5. Reboot

Your network drive should work normal again.

Background and Explanation:

The PROVIDERFLAGS instruct Windows to reconnect the SMBv1 network drive, more or less. It eventually did not matter if it was connected per FQDN, IP or HOSTNAME – is was the reconnect that the GPO implied, respective the NET USE /PERSISENTENT:YES switch. If you would use a script – netlogon script – you could just determine the drive as /PERSISTENT:NO and not see the issue either as well as solve it.

Eventually this is specific to SMBv1 and I can’t warn enough about the security risks this protocol has. Still – there are here and there systems that still need to stick around – hopefully secured by firewalls and even sandboxes etc..