HOW TO FIX: Sound not working in Windows 8 - 'Error 0x800706cc: The Endpoint is a duplicate'

There have been many reports on the Internet recently of a problem affecting sound playback in Windows 8/8.1 caused by the accidental removal of system files by AVG anti-virus.

The symptoms include:

- Complete loss of audio
- A red cross over the speaker icon in the system tray (bottom right corner) area of the screen.
- Unresponsive navigation of the Windows Control Panel causing explorer.exe to hang.
- Inability to start the 'Windows Audio' service with the error message Error 0x800706cc: The Endpoint is a duplicate.
- Inability to start the 'Network List' service with the error message Error 127: The specified procedure could not be found.
- One or more system files in AVG quarantine (this can vary).

Many reports indicate that restoring the system files from the AVG quarantine restores normal sound and Control Panel operation. On the Toshiba laptop I was working on, there was evidence of a Printconfig.dll file having been recently 'secured' but no sign of it existed in the quarantine, so this was not an option. The file name itself seems to vary, with some accounts of the problem mentioning a 'launcher.exe' file instead.

What was strange about the problem is that the regular 'SFC' and 'DISM' tools did not recognise any missing or corrupt files, so it was very difficult to find out exactly what was missing. After a lot of Internet searching, I finally came across a post by Nathan Mixter at http://superuser.com/questions/814671/cant-enable-windows-audio-on-windows-8-1. Nathan had fixed the problem by using a a free program called 'Windows Repair', available to download from http://www.tweaking.com/content/page/windows_repair_all_in_one.html.

I was sceptical at first, but started the 'repair' section of the program running with its default options ticked and left it to process overnight. After about 8 and a half hours it finally finished, and on restarting the computer I was amazed to discover that the sound was now working again. Whatever it was doing it all that time remains a mystery, and I have no idea what file or registry key was preventing the audio service from starting. If anybody knows, I would be really interested to hear from them.

Unfortunately, the problem with the unresponsive control panel remained. After examining the event logs, I found that it was caused by a faulty 'Network List' service which would refuse to start with the message Error 127: The specified procedure could not be found. Disabling the service seemed to restore normal operation, but I wasn't sure what the consequences of leaving it disabled might have been.

After a lot of trial and error, I was able to finally repair the problem by extracting the registry key that controls the 'Network List' service from a working computer and then importing it into the computer with the problem.

Key for the 'Network List' service:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\netprofm

After a reboot, the service started without error and the Control Panel worked normally.

To fix this on your own machine, download the file 'netprofm.reg' from the following link:

https://sites.google.com/site/wintegrity01/netprofm.reg

Once downloaded, double click on the file and accept any warnings that appear. This will import a working 'Network List' registry key and it will automatically replace the faulty version. After restarting the computer, the Control Panel should be back to normal.