Please help me turn my webcam off! (So that I can use it)

January 18, 2009 10:46 PM

ComputerTroubleshootingFilter: My google-fu has failed me. How do I turn my webcam "off" so that I can have programs turn it on and use it?

I have an HP VGA Webcam EW193AA webcam, and for quite a while, it's been working quite well.

I unplugged it a few days ago, set it next to my computer, and replugged it in today. (Being a plug and play device, this's something I do rather often, never had problems before)

Normally, when I plug it in, Windows makes it's little "ba-dum" noise of a plug-and-play device being plugged in... then the inverse "da-bum" of a plug-and-play device getting unplugged. At the same time, the little indicator light flickers on... then turns off.

Whenever a program starts using the camera (like connecting a skype call, or opening it for use in a video-capture program), I hear the plugin ba-dum... and it works, and the light stays on the entire time that the camera is in use.

Today when I plugged it in, the light stays on.
I've tried restarting the machine, both with it plugged in and without.
I've uninstalled then reinstalled the initial factory drivers.
I've found the latest updated drivers from HP... installed them.

When I try to capture video from the camera, skype tells me the webcam is in use, and other programs tell me that it's being used by twainUI. (I've no idea what that is except that it seems to be related to printer/scanner spooling)

So. My question:
How do I find out what programs are using the camera? (so that I can close it and start using the camera by choice)
or
How do I circumvent whatever program's using the camera so that I can use it?

Thank you all.

posted by Seeba to computers & internet (4 comments total)

Oh. A look through running processes and open programs doesn't show anything remotely resembling "twainUI". So I'm not sure what/how that's being used. A quick google search shows me it's a .dll file, but I've no idea how the computer uses those- or how I'd trace the program using the file.
posted by Seeba at 10:53 PM on January 18

A highly general answer, if you're willing to go through the trouble: Process Monitor traces all kinds of things that applications do, loading DLLs being one of them.
posted by themel at 11:46 PM on January 18

Right-click on the task bar, select task manager. Under processes look for any item that might be using the camera. Kill the process and see if the camera works. If so, you've found your culprit, and the next step is preventing that application from loading on startup. Look for it under services (Start -> run -> services.mcs) and disable it.

I'm betting that in all your disconnecting and reconnecting of the camera, Windows sees it as a new device and has assigned a particular application to it... perhaps one of the built in Windows capture apps, etc.
posted by wfrgms at 4:56 AM on January 19

I've closed everything that I've access to (the task manager won't let me close some OS related stuff- csrss.exe, etc)-- (also, I reopened firefox to answer this), and it doesn't go off... I will try this process monitor program, see if I can track it down.

You're probably right about the built in windows capture apps-- I'm running vista, do you happen to know where I can find them? (under processes/services would be ideal, so I can just turn 'em off)

Thank you.
posted by Seeba at 12:00 PM on January 19