While setting up a new Windows 10 laptop we ran into a head-scratcher problem. We store a lot of our setup data in a network attached storage system called a QNAP. The laptop was connected to our local area network over Wifi, and everything connection-wise looked to be good. We could ping both the IP address of the QNAP and the DNS name as well, so we knew for a fact that the laptop could indeed send and receive traffic with the QNAP. When we attempted to call up the QNAP using Windows Explorer on this laptop we used the UNC convention to get to our data, like this \\10.1.1.100 and when we press enter, Windows 10 would pause for a short few seconds and then throw back an error code:

Windows Cannot Access \\10.1.1.100 Error Code: 0x80004005 Unspecified Error.

We then attempted to reboot, then we escalated to a full system rebuild and nothing seemed to work for us. We fiddled with PowerShell commands, to no effect, also flipping on and off IPv6, which also had no effect. So our next step was to switch to wildcat debugging and just start taking wild potshots at the laptop trying to find a way to just make this work. And we found the solution, thanks to a user by the name of dimamed on Spiceworks, who posted the solution we needed:

Adjust Registry Value:
HKLM\SYSTEM\CurrentControlSet\LanmanWorkstation\Parameters\AllowInsecureGuestAuth, and set the DWORD to 1.

Then I closed the registry editor, opened up Windows Explorer again, tried the QNAP as I usually do and it worked! We don’t really need it to function for our end users, but it became a matter of professional pursuit to make sure that all our technology can work together properly. It can, with some coaxing.

We hope this solution works for other folks, if you also run into this issue. Please leave a comment if you would, so we can see just how much of an impact something like this has if you don’t mind.