Connecting to NAS - "Windows cannot access"

What NAS (name and model) are you running?

I'm running a WD NAS (PR4100) and Windows 10 is handling it just fine. I can also map drives, which means I have to input my credentials. That also works just fine under Windows 10.

BTW your screenshot alludes a spelling error. Did you double check? Also, under Network, in Windows Explorer, do you see your NAS drive under Storage? If not, either the PC isn't on the same network, or there's a network problem.

THX1138 said:

Not the experience one expects from the world's leading OS.

If the OS was really the problem, none of your Windows 10 machines would work. That doesn't seem to be the case as you stated here...."

THX1138 said:

even though it works fine from another Windows 10 machine and it worked one time (about an hour ago now) on this machine.

With that, are all the machines on the same network?

Regardless, the issue isn't an OS problem, but appears to be a network problem. You might also doublecheck the NAS drive isn't going offline.

Let us know.

Change your NAS to use SMB 2.0 at a minimum and disable SMB 1.0 if you can. Windows 10 1809 will now throw the error you are getting when the device you are trying to connect to requires SMB 1.0

Why? How? Reason?

I certainly didn't have to do such a thing, even when I did get an access denied error.

And under Windows 10 (1809) SMB 1.0 isn't enabled by default anyway.

It has nothing to do with Windows other than their security updates have caused the issue.

Not knowing your make a model of NAS I cannot tell you how to change these settings on that device. You should have a user manual that can help or you can look for a manual online that may assist you.

The NAS in question is a Synology DS215j. I think it is to do with Windows because it works fine all the time on my mum's laptop running Windows 10 and sporadically on this machine running Windows 10. SMB 1.0 is already disabled on my machine (as it is by default).

Like I said it needs to be disabled on the NAS itself. You need to use the WEB GUI interface to the DS215j and verify the settings. Besides SMB1.0 needing to be disabled you need to determine that you are on the same Domain. The last Oct. update removed the HomeGroup from Windows networking so all that is left is Workgroup for a Domain name. NetBIOS and Wins Server are other factors that can play into this picture as well even though they are far less likely.

The UI doesn't differentiate between SMB versions.

Did you look in the Advanced Settings section of SMB to see way options may be available? Did you click on the Advanced tab of the File Services screen shown in your screenshot to check for available options? Other functions like NteBIOS and WINS might be found in the Network section.

Since I do not own a Synology NAS I am not familiar with the interface.

You're right; they're in the Advanced Settings but changing these to Min = 2 or Min = 2 and large MTU and Max = 3 has not changed the error I get (0x80004005).