Error, this module is blocked from loading into Local Security Authority Bonjour/mdnsNSP.dll

Question

Usually once per today, while doing nothing, I get the pop up that module is blocked from loading into LSA, and its a folder Bonjour/mdnsNSP.dll.

Does anyone know how to fix this? What is happening. Thanks

Answer 1

Usually once per today, while doing nothing, I get the pop up that module is blocked from loading into LSA, and its a folder Bonjour/mdnsNSP.dll.

Does anyone know how to fix this? What is happening. Thanks

I have the issue but have neither itunes or anything apple related installed

Please download and run Autoruns as administrator.

Autoruns - Sysinternals | Microsoft Learn: https://learn.microsoft.com/en-us/sysinternals/downloads/autoruns

In the search text box, type bonjour and press Enter.

Select the Everything tab.

Post a screenshot.

Answer 2

This is the screenshot. Any help?

Answer 3

After modifying my registry as you specified above, my PC fails to boot. I needed to restore the system stored 3 days ago to make my PC work again. I do not recommend to do this!

Answer 4

After modifying my registry as you specified above, my PC fails to boot. I needed to restore the system stored 3 days ago to make my PC work again. I do not recommend to do this!

Sorry to hear that. When I tested Autoruns today, it didn't update a registry value after removing the Winsock provider entry. This is clearly a bug in Autoruns, which caused a reboot loop at startup. This happens because Autoruns fails to update the "Num_Catalog_Entries" and "Num_Catalog_Entries64" registry values. Fixing this using offline registry editing resolves the issue.

However, the following are the preferred methods. Be sure to backup the registry beforehand.

Option 1: Unregister mdnsNSP.dll

Important: Please backup the registry using AceLogix RegBak because the following steps modify the Winsock setting. Additionally, create a System Restore Point.

From an admin Command Prompt, run these two commands to uninstall the Bonjour DNS module:

• regsvr32 /u "C:\Program Files\Bonjour\mdnsNSP.dll"
• regsvr32 /u "C:\Program Files (x86)\Bonjour\mdnsNSP.dll"

The above commands unregister the mdnsNSP.dll, thereby removing the Winsock entry properly.

Option 2: Reinstall iTunes 12.4.3 classic setup and uninstall it via Programs and Features.

• Download iTunes 12.4.3 for Windows (64-bit) - Apple Support: https://support.apple.com/en-us/106379

Important: This old software can cause instability on some Windows 11 systems because of the older iTunes version. If Explorer doesn't load after installing iTunes 12.4.3, open Task Manager and launch "appwiz.cpl" to launch Programs & Features. Uninstall iTunes and the following items:

• Apple Application Support
• Apple Mobile Device support
• Apple Software Update
• Bonjour

mdnsNSP.dll (Bonjour) is Blocked from loading into LSA: https://www.winhelponline.com/blog/mdnsnsp-bonjour-blocked-lsa/

(edited)