'Access is denied' message when trying to connect to NAS share drives

Hi! My name is Anderson Souza. I'm an Independent Advisor and a Microsoft user like you, I'll be glad to help you today.

Your Windows is home or professional?

The problem began after updating to 2004 version? If so I strongly recommend doing a rollback to the previous version.
You can try to do a system restore to undo the update that caused the problem. In the link below is an official guide from Microsoft showing how to perform this procedure:

https://support.microsoft.com/en-nz/help/12415/...

These are the options you are currently looking for?
1 - Remove an installed Windows update
2 - Restore from a system restore point (choose a date prior to the problem if available).

Your Windows is the Home or Professional edition?
If it is Professional you can try this also:

Use “Start->Run” and type in “gpedit.msc” in the “Run” dialog box. A “Group Policy” window will open.
Click down to “Local Computer Policy -> Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options.
Find the policy “Network Security: LAN Manager authentication level”.
Right click on this policy and choose “Properties”.
Choose “Send NTLMv2 response only/refuse LM & NTLM”.
Click OK and confirm the setting change.
Close the “Group Policy” window.
You are done configuring Windows! Now configure your browser(s).

You can try different LTLM Levels. Here is more about this:
https://docs.microsoft.com/en-us/windows/securi...

But I have seen many network share problems after 2004 version and until now they were resolved buy downgrading Windows.

Keep me posted.

Hi Anderson,

I have Win10 Pro

The system won't let me restore back to 1909. The problems started appearing about 2 weeks ago after a KB upgrade on 1909. I thought the upgrade to 2004 might resolve it but alas no.

I have tried both "Send NTLMv2 response only/refuse LM & NTLM” and "Send LM & NTLM - use NTLMv2 session security if negotiated"

Neither fix the problem

Do you know what exactly the KB was that caused the problem? So we can refine the search for the solution.

Unfortunately I deleted the update history...part of one of the possible remedies I read online!

It would have been a KB update to 1909 sent between July 15th and July 20th. I noticed the behaviour first on July 20th when I couldn't access a drive on the NAS

Your NAS device support NFS? Your Windows 10 is the Pro version? Do you oppose to try enabling an NFS share and check if the problem only occurs with SMB share? This is not a solution, it is more like a workaround, but it is just a suggestion.

Unfortunately my NAS doesn't have the NFS option in the settings

Ok. Another option you can try is enable SMBv2 on your NAS device or try to enable guest access to the share (no credentials required).

I also found this thread:

https://answers.microsoft.com/en-us/windows/for...

That mentions this:

https://community.spiceworks.com/topic/2277832-...

"The trick is to add the registry key "ProviderFlags" as a REG_DWORD with a value of 1 (0x00000001) to HKEY_CURRENT_USER\Network\*SMBv1 Drive Letter*

Then reboot or log on/off. It fixes the perpetual "reconnecting" status of the SMBv1 drive at logon and everything has been functioning normally and quickly for users we've added that registry key. Only needs to be added to the drive letters under Network that correspond to SMBv1 shares."

Here is the Microsoft Advanced Troubleshooting Server Message Block (SMB) article:
https://docs.microsoft.com/pt-br/windows-server...

Tell me if something works. Until now I've only seen this problem solved by rolling back updates or reinstalling Windows.

Unfortunately the HKCU trick didn't work. I didn't have any drive letters under Network. I tried adding one to see if that would work but it didn't.

Also my NAS is an old IomegaEZ one which was taken over by Lenovo. The user setting page is **** and the last firmware update was over a year ago. You can't set the SMB level.

The thing is the NAS is working fine so I feel reluctant to throw it out and get a new one. At the moment I have it network connected to a Win7 laptop where the functionality is as it was!

I was using the NAS as a media server so I guess I'll just use the Win7 laptop to access the shares.