Strange network problem

[denis1304]

I have a strange network problem, that started all of a sudden.
There wasn't any hardware or software changes.
I have wired network to the router to access another PC that also have wired connection.
In the Explorer I can see all the PCs that are on my network.
When I start my PC and I try to access my network, system asks me for password (even thou, my PW should be saved by the system), and if I input my PW it say the PW is wrong.
The router is also has WIFi.
So I used a WiFi dongle to access router (without restarting my PC, system telling me my PW is wrong and me not be able to access other PC), and everything works as it should without me having to input PW or anything. It just works...
Then I removed the dongle and I can still access network over wire until I restart my PC.

Before "dongle" I can't access the other PC using VNC, after I can.

Anyone have any idea what is going on here?

 

[tech291083]

That is a strange one — but it actually fits a few known Windows networking quirks.
Let’s break it down logically and then go through how to fix it. The following is based on my personal experience for Windows 7 Ultimate 64-bit, but many years ago. Not sure the steps below really work today or not. Good luck.

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[h=2] What’s probably happening[/h] When your PC boots with only Ethernet, Windows 7 can’t properly identify the network and classifies it as Public or even Unidentified network.
In that mode, file sharing, SMB authentication, and VNC are all restricted. That’s why it says your password is wrong (it’s really blocking the login).
Then, when you plug in your Wi-Fi dongle, Windows suddenly recognizes the network, merges its profiles, and switches both interfaces to Home (Private) network type — and everything starts working. After removing the dongle, the working profile stays cached until reboot.

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[h=2] Step-by-Step Fix[/h] [h=3]1. Check your network type[/h]

• Open Control Panel → Network and Sharing Center
  
• Under your active wired network, see what it says:
  
  • “Home network” → good
    
  • “Work network” → fine too
    
  • “Public network” → that’s your problem

If it’s Public, click it and choose Home (or Work) network.

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[h=3]2. Ensure “Network Location Awareness” is working[/h] Sometimes the NLA service fails to start or can’t identify the network.

1. Press Win + R, type services.msc, press Enter.
   
2. Find Network Location Awareness → it should be Started and Automatic.
   
3. Do the same for:
   
   • Network List Service
     
   • Network Store Interface Service

If any are disabled, enable and start them.

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[h=3]3. Reset network profile cache[/h] If Windows keeps misidentifying the network:

1. Open Registry Editor (regedit.exe).
   
2. Navigate to
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Profiles
   
3. Under Profiles, you’ll see one or more long GUIDs.
   
   • Each corresponds to a network Windows “remembers.”
     
   • You can delete the ones for your Ethernet adapter (or all of them).
4. Reboot.
   When you reconnect the cable, Windows will ask “What type of network?” — choose Home.

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[h=3]4. Verify discovery and sharing settings[/h] Control Panel → Network and Sharing Center → “Change advanced sharing settings”
Under Home or Work:

• ✔ Turn on network discovery
  
• ✔ Turn on file and printer sharing
  
• Turn off password-protected sharing (for testing)

Save changes and retry.

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[h=3]5. Reset the TCP/IP stack and Winsock[/h] Open Command Prompt as Administrator and run:
netsh int ip reset
netsh winsock reset
ipconfig /flushdns
Then reboot.

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[h=3]6. Confirm DHCP and IP info[/h] After reboot (and before using Wi-Fi), open a command prompt and run:
ipconfig /all
Check that your Ethernet adapter has:

• An IP address like 192.168.x.x (same range as your Wi-Fi)
  
• A valid Default Gateway (your router’s IP)
  
• No “169.254.x.x” self-assigned address

If the IP range is wrong, DHCP isn’t working over Ethernet — fix that in the router or set a static IP.

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[h=3]7. Optional: Disable “Network Identification” timeout bug[/h] Sometimes Windows 7 fails to classify the network if the router doesn’t reply quickly.
A registry tweak can help:

1. Run regedit
   
2. Go to
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NlaSvc\Parameters\Internet
   
3. Right-click → New → DWORD (32-bit) Value
   Name: EnableActiveProbing
   Value: 1
   
4. Restart your PC.

This makes NLA actively probe the gateway and correctly recognize your LAN.

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[h=3] What to expect after fixing[/h]

• After reboot, Ethernet should show as “Home network.”
  
• You should be able to access other PCs and VNC immediately.
  
• You won’t need to plug in the Wi-Fi dongle anymore.

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If you want, you can paste here:
ipconfig /all
and
net view
outputs before and after connecting the dongle — I can confirm whether it’s purely the network profile or a DHCP/routing issue.

 

[denis1304]

I switched from Home to Work network, and network worked without me using WiFi dongle...
Will se if it works on the Monday.

 

[Laurent67]

Windows 7 was treating your wired network as Public, which blocks SMB/VNC logins even if the password is correct.
When you switched it to Work, Windows finally allowed LAN authentication, that’s why it works now.
If you want a clear explanation of how this kind of filtering works, here are two solid references:

What Is ACL and How It Works
Configure Commonly Used IP ACLs - Cisco