Shares not accessible by other computers if Windows 10 firewall is ON

I had the same problem, and @JacobBoykin's answer made to look in the right direction. But it's not only about being on a private network for a "private network" firewall rule to apply. Note that a few columns further to the right, the scope of many (at least all private) rules is set to "Local subnet", such as here:

In my case, I was connecting to a server on 10.0.0.2 (having subnet mask 255.255.255.0) from a client computer 10.1.0.3 (subnet mask 255.255.255.0); hence, the server's firewall did not recognize my request as coming from the same subnet, and did not apply the "private" rule. Similarly, since my current network was marked "private", the "public" rule was not applied. Regardless of how many rules I activated, no request came through.

The solution, in my (DHCP) case, was to edit rules to extend the scope; basically, I added "10.1.0.0/16" to the scope of the private "File and Printer Sharing (SMB-In)", which opens port 445 to requests from that IP range. That was enough in my use case.

Alternatively, I guess I could have changed my IP configuration to have all computers on the same subnet.

I have the same problems, with folders on 2 Windows 10 computers, and I get it fixed.

1. Firstly, go to Windows Defender Firewall on Local Computer (that has shared folders) then select Advanced settings Windows Defender Firewall with Advanced Security

2. In Inbound Rules, double click on File and Printer Sharing (SMB-In) and in the tab Scope add your Remote Computer's IP address here. Click Apply File and Printer Sharing (SMB-In) Properties

3. Problems resolved!

I'm assuming your computers are not members of a domain, correct? I would double check your network location settings for your Ethernet connection and verify it is set to private before digging into Firewall settings.

http://www.tenforums.com/tutorials/6815-network-location-set-private-public-windows-10-a.html

I had this same issue but when I looked at the advanced firewall rules I discovered that port 445 was already open. In my case it was because I was on a different VLAN. I fixed it like this:

1. In the search box, type "firewall," then click on "Windows Firewall."
2. Click on "Advanced Settings."
3. Double-click on "Inbound Rules."
4. Make sure the lines "File and Printer Sharing (NB-Session-In)" and "File and Printer Sharing (SMB-In)" are checked.
5. Double-click on "File and Printer Sharing (NB-Session-In)" and select the tab that says "Scope" and change the remote address setting to "Any IP Address" then click "OK."
6. Repeat on the line that reads "File and Printer Sharing (SMB-In)."
7. I also wanted the server to ping on the net so I did the same with the setting for "File and Printer Sharing (Echo Request - ICMPv4-In).
8. I also wanted name resolution, so I adjusted the scope for File and Printer Sharing (LLMNR-UDP-In) and (NB-Name-In).

There's a good explanation of these settings here.

Well, this worked for me... give it a go.

Go to Start, type Command Prompt (run as admin) in the search bar, at the command prompt enter the following commands. Its easiest to copy and paste from below, and press Enter after each paste:

sc.exe config lanmanworkstation depend= bowser/mrxsmb10/nsi

sc.exe config mrxsmb20 start= disabled

Then reboot your Windows 10 machine;

This should do the trick.

When sharing wasn't working for me on a very recent install, I gave up and reset firewall to defaults then re-enabled file sharing and let Windows get the settings right. I noticed as I did this one of the prompts was to "make the network I am connected to a private network" - this despite it already appearing to be labeled Private before. I suspect this Public/Private setting was somehow silently out-of-sync (as I bounced between two PCs signed in with a Microsoft account?) and was the cause all along.

1. Windows Security -> Firewall & network protection -> Restore firewalls to default

   

2. Click "Restore defaults" button, answer "Yes" to the warning prompt (Note: you'll lose any custom firewall settings and will be prompted again with Windows Defender pop-ups as you [re-]open programs that use networking)

   

3. Visit Network in an Explorer window, click the "File sharing is turned off" banner then "Turn on network discovery and file sharing"

   

4. If you are prompted with "Do you want to turn on network discovery and file sharing for all public networks?" you probably want the first option "No, make the network that I am connected to a private network"