Can see files in folders shared on Win7 machine, but cannot open them

Four devices are connected to the Ethernet ports of the broadband router provided by my ISP: a Win7 Home Premium PC, a Win10 Pro NB and two Linux media players.

The only problem with respect to file sharing among these devices is that the Win10 Pro NB can see, from File Explorer, the files in the shared folders of the Win7 HP PC, but can not open them, whatever the file type is.

For example, when I click on an MP4 file in a shared folder of the Win7 HP PC, Win10 Pro's "Movie & TV" starts to open it, but fails, popping a message saying there is a 0x80004005 error.

How can I get it fixed? Please help.

This problem does not exist until recently, and seems to occur after a certain Win10 update, but I'm not sure.

Win10 Pro is on version 1709 build 16299.492.

More info...

(1)

I know SMBv1 is removed from Win10 since version 1709. But, weirdly, on my Win10 version 1709 machine, SMBv1 still exists because the "State" of "SMB 1.0/CIFS file sharing protocol" is detected as "Enabled" when the follwing command is executed from PowerShell, as instructed by this MS support article:

Get-WindowsOptionalFeature –Online –FeatureName SMB1Protocol

On the other end, SMBv1 server and client also exist on my Win7 machine as detected to be so with the methods provided by the same MS support article above.

Therefore, maybe SMBv1 shouldn't be an issue?


(2)

When Windows Firewall is turned off on both Win7 and Win10, Win10 still can not open files in Win7. (Both computers use the Private network profile for LAN.)


(3)

Multi-media files in Win7 can be opened from Win10 successfully through UPnP by Windows Media Player 12.


(4)

The two media players runs on BuzyBox v1.1.3. They have workgroup and UPnP functionalities, but they are not computers. By the way, I know virtually nothing about Unix.

(5)

When I tried to use the "Go back to the previous build" option in the "Advavnced Options" of Win10's startup menu, the previous build could not be restored because there had been a problem... unexplained.

Now I have noticed the following:

(1)

It's incorrect that files of any type can not be opened. Actually, only videos, audios and graphics can't be opened by their associated programs:"Movies & TV" and Photos. Files of other types, such as rtf, doc, xls, ppt, pdf can be opened by their associated programs. Zip files can be opened straight in File Explorer. Files whose names lack extensions are associated with a text editor I use and can be opened by it.

(2)

If I resort to the "Open with" item of the right-click menu and choose Windows Media Player 12 to open videos and audios, they can be opened successfully. In the same way, graphics can be opened by Paint.

(3)

If I copy, from the Win7 PC, those videos, audios and graphics that can't be opened by "Movies & TV" and Photos to the media players, those same files in the media players can be opened by "Movies & TV" and Photos from the Win 10 NB.

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I'll try the un-installation of the recent Win10 updates when I have more time later.

Those shared folders in Win7 are shared with EVERYONE indeed.

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Now, something very interesting...

If I log into the Win7 PC from the "Open file" dialog window of ANY program in Win10, either before or after logging into Win7 from Win10's File Explorer, I won't have any trouble with opening videos, audios and graphics, with their associated programs, i.e., "Movies & TV," "Groove Music" and Photos.

> If you open file explorer on the Windows 10 machine and double click on a file on the Win 7 machine,
> say a movie, it won't open.

Correct.

> However if you start Movie Player on Window 10 machine and then within the program (app) you use
> open file on the Win 7 machine it works.

No. Actually I can't find an "Open file" feature within "Movies & TV", "Groove Music" and Photos. So, I can't log into Win7 from those apps.

But I can log into Win7 using the "Open file" dialogue window of some other programs, such as AkelPad (my text editor), PotPlayer (my video player) and OnlyOffice (my MS Office replacement).

As I said before, after I log into the Win7 machine from Win10 File Explorer, I can't open Win7 shared files associated with "Movies & TV", "Groove Music" and Photos. But if I log into Win7 again from the "Open file" dialogue of other programs, and then come back to File Explorer to open the same files on Win7, I can open them now!

Or I can first log into Win7 from an "Open file" dialogue, and then log into Win7 again from File Explorer. Then I won't have trouble opening Win7 files from File Explorer, too.

Speaking more specifically, after I log into Win7 again from an "Open file" dialogue, I don't even need to proceed to really open any file. Just log in and that's enough.

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Another trouble is that after logging into Win7 from Win10 File Explorer, I can not copy any Win7 shared file of any type to the Win10 machine. When I attemp copying, either nothing happens or the copy process is stuck at 99%.

But after another logging from an "Open file" dialogue, file copying can be successful.


PS_1:

Later I notice that I can use the "Select folder" dialogue of the "Add a folder" functionality of "Movies & TV", "Groove Music" and Photos to log into Win7. That has the same effect as using an "Open file" dialogue of other programs.

PS_2:

I also notice that If I "turn off password protected file sharing" on Win7, then there is no problem to open Win7 shared file from Win10 File Explorer. No more need for logging into Win7 again from an "Open file" or "Select folder" dialogue.

That leads me to imagine that when "Movie & TV", "Groove Music" and Photos are invoked to open Win7 files from File Explorer, maybe they encounter an invisible login screen thrown up by Win7, which prevents them from further accessing files, even though logging has been accomplished by File Explorer. But that's only a wild guess.