Logitech C930e webcam not functioning

Hello Richard,

Thank you for choosing Microsoft Community.

What is the make and model of the computer?

Based on information you have provided, there can be a possibility that USB ports itself may not be functioning properly.

I would suggest you to try following steps:

Step 1: Open the Hardware and Devices troubleshooter
http://windows.microsoft.com/en-us/windows7/Open-the-Hardware-and-Devices-troubleshooter

Hello Richard,

First we appologize for late response.

Hi Jayant,

This device does not work with Skype nor with any desktop / web applications.

However further T/S have been completed. I am convinced this issue is driver related.

-sfc /scannow completed with no integrity errors

-Tried using manufacturers drivers from other models of webcams - No luck

Investigated further into virtual Windows 7 x64 - again device works perfectly. However found a difference:

Left his my system as host. Right is another copy of Win7 x64 Ultimate in VMWare (Virtual) with similar hardware configuration.

Why does Virtual Win7 chose to utilize ksthunk.sys while my computer (host), only utilizes usbvideo.sys and not ksthunk.sys as well?

I do have a feeling this ksthunk.sys driver along with usbvideo.sys is what makes the device work. However I don't know how i can force this driver use that sys file along with usbvideo.sys.

Any further assistance would be appreciated.

Hello Richard,

Thank you for your reply.

You may try following methods and check:

Method 1: Disable Security Software and check

Disable antivirus software

http://windows.microsoft.com/en-us/windows/disable-antivirus-software#1TC=windows-7

 Note: Antivirus software can help protect your computer against viruses and other security threats. In most cases, you shouldn't disable your antivirus software. If you have to temporarily disable it to install other software, you should re-enable it as soon as you're done. If you're connected to the Internet or a network while your antivirus software is disabled, your computer is vulnerable to attacks.

Method 2: Place the computer in clean boot state and check for conflicting application

Note: After you have finished troubleshooting, follow these steps from section “How to reset the computer to start normally after clean boot troubleshooting” to reset the computer to start as usual.

Method 3: First Create a system restore point and Delete upper filter in below registry key.

Create a restore point

http://windows.microsoft.com/en-US/windows7/Create-a-restore-point

Then before going to following registry key backup registry before making any changes as

serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

How to back up and restore the registry in Windows

Go to the registry location HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro​l\Class\{6BDD1FC6-810F-11D0-BEC7-08002BE2092F}.
Check for Upper filter with the value as KTHUNK and delete the Upper Filter and then check.

Hope this information helps. Please reply with the status so that we could help you further.

Hi Jayant,

I reply with good news. The first two methods were unsuccessful. However the third method was half the solution.

The key UpperFilter did not have a value of KSTHUNK, however the value was ASMFilter. I deleted this key and uninstalled current driver for the device and rebooted but the issue was still present.

I went back into the registry, Re-added the key UpperFilter but instead of placing value ASMFilter I placed ksthunk. Re-performed uninstall of driver, rebooted and I can now happily say the usbvideo.sys and ksthunk.sys is being utilized and the device is WORKING perfectly.

I must thank you very much for leading me to the solution Jayant, and your assistance was greatly appreciated.

Thanks again.

Regards,

Richard.