
Last Update: October 20, 2025
BYeric
Keywords
I run a custom trading gateway on a Windows 10 machine, primarily because it needs to interface with MetaTrader 5. I rely on MetaTrader to access market data and place orders for specific symbols and exchanges, like the ASX, that aren't available through my other tools. This setup is usually reliable, with the gateway using an SMB-based shared drive for data storage. However, that stability broke after I upgraded the machine to Windows 11, a necessary move with Windows 10 support ending. The first challenge I hit was the gateway losing access to its SMB share, which means I could no longer save the market data to the shared drive where my other pieces of trading software read the data from.

After some investigation, I found that Windows 11 had tightened its security around SMB guest authentication, which was causing the connection issues. The data server hosting the SMB share only supported guest access without authentication, and with the new security measures in place, Windows 11 was blocking the connection.
Quick sanity checks
Before diving into configuration changes, I ran through a checklist to rule out common issues:
- Verified the NAS was still reachable by IP using
ping
andTest-NetConnection
. - Confirmed other machines on the LAN could mount the share, isolating the failure to the trading PC.
- Cleared cached credentials with
cmdkey /list
andnet use * /delete
. - Rebooted after installing the latest cumulative Windows updates in case a patch hardened SMB defaults.
⚠️ Security note: Insecure guest logons remove authentication from SMB connections. Only use this on a machine you control, on a trusted network, and keep it firewalled from the public internet. Disable the setting again once you retire legacy storage.
The fix: allow guest logons again
A simple way to allow guest logons again is to enable the "insecure guest logons" setting via Group Policy as follows.
-
Enable Insecure Guest Logins via Group Policy:
- Press Win + R, type
gpedit.msc
, and press Enter to open the Group Policy Editor. - Navigate to Computer Configuration > Administrative Templates > Network > Lanman Workstation.
- Double-click Enable insecure guest logons and set it to Enabled.
- Apply the changes and restart your computer.
- Press Win + R, type

However, if you are using Windows 11 Home, you will need to use the Registry Editor method, as Group Policy Editor is not available.
-
Enable Insecure Guest Logins via Registry Editor:
- Press Win + R, type
regedit
, and press Enter to open the Registry Editor. - Navigate to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters
. - If the
AllowInsecureGuestAuth
entry does not exist, right-click and select New > DWORD (32-bit) Value, and name itAllowInsecureGuestAuth
. - Set the value of
AllowInsecureGuestAuth
to1
. - Close the Registry Editor and restart your computer.
- Press Win + R, type
After making the group policy change, you may still not be able to connect to the SMB share. The difference is that you probably don't have to wait for a few minutes for that error to come up. If you try to connect to the SMB share via net use
, you may see an error like this:
C:\> net use Z: \\data-server\share
System error 3227320323 has occurred.
Try running the following command via PowerShell:
Set-SmbClientConfiguration -RequireSecuritySignature $false
The above command is a PowerShell cmdlet that controls the SMB client "RequireSecuritySignature" setting. Running it sets whether the SMB client requires SMB packet signing for connections (our instance sets RequireSecuritySignature
to $false
). The error 3227320323
indicates that the SMB client is requiring security signatures, but the server does not support it. So when set to true (the default), connections to servers that do not support signing will fail.
Restart your computer after running the command. After that, you should be able to connect to the SMB share again.
Conclusion
After upgrading to Windows 11, I encountered SMB share connectivity issues due to Windows 11's stricter security policies around guest authentication. By enabling insecure guest logons through Group Policy (or the Registry Editor for Windows 11 Home) and disabling the security signature requirement with PowerShell, I was able to restore access to my legacy SMB share. This allowed my MetaTrader 5 gateway to resume saving market data to the shared drive.
Remember that these changes reduce security, so only apply them on trusted networks and on machines you control. Keep your firewall enabled and consider upgrading your storage solution to support modern authentication methods when possible.
Previous Article

Oct 03, 2021
Setting up Ingress for a Web Service in a Kubernetes Cluster with NGINX Ingress Controller
A simple tutorial that helps configure ingress for a web service inside a kubernetes cluster using NGINX Ingress Controller
Next Article

Oct 05, 2025
From Broken Fractions to Beautiful Formulas: Claude Code Trumpeted the Game!
A real-world comparison of Google Gemini, OpenAI Codex, and Claude Code in debugging a MathJax rendering issue. Spoiler: only one AI actually fixed it.