So, a couple of years ago I was the first person in the office upgrade to Windows 8. I had the blessing of corporate IT as long as I troubleshoot my own problems if they were Windows 8 specific. And of course if I encountered and fixed any errors let them know what it was and how to fix it.
One of the first problems I encountered was problems connecting to our $50k SAN. After some digging it turned out that it did not support a new SMB feature turned on by default in Windows 8 called Secure Negotiate. Which basically wants to negotiate with the server about which encryption to use when transferring files. A solution was quickly found: Turn off the feature.
This could be done setting the following registry key:
HKLM:\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\RequireSecureNegotiate=0
Everything worked as expected until I upgraded to Windows 10 when that came out. Microsoft had a very valid reason to remove the above workaround and not allow you to bypass any security features unless the server indicated during negotiation that it would not support certain things.
However, the SAN still didn’t support any secure negotiate feature. So after some more research I found out that I could just tell the client to force secure transfer without the need for negotiation. So if you can’t seem to access your SMB shares anymore since upgrading to Windows 10, open a Powershell prompt as Administrator and run the following command:
Set-SmbClientConfiguration -RequireSecuritySignature $true
Please note that I am not an SMB protocol guru so the above text may be a bit inaccurate in its details. If you want more info however, someone at Microsoft who does know what he is talking about did a very detailed write-up about the feature. You can find it here: