Not meaning to rehash any previous threads, but I'm at a loss. I'm pretty good technically and driven until I usually fix things, but this one just plain has me stumped. I have a Quickcam Ultra that worked fine on Vista. I did a clean install of Windows 7 64-bit (7000) on my machine (Intel dual core, 4GB RAM) and as I remember, the install recognized my camera, did a web driver install (stating compatibility issues of course) and the camera briefly worked. However, it immediately stopped working and I have been through multiple reinstallations - starting with Logitech's software online for Vista (11.5), letting Windows upgrade it to 11.8. The Device Manager says the device is installed correctly and working. However, no application will activate the camera (Quickcam, Skype, Live Messenger) - they all say the webcam is in use by another application and to close the application. I have no idea what application it could possibly be talking about. I found a Quickcam 11.9 version online as many people have been saying this works for them. It installed correctly, but I still have the same issue. I also have a ATI tv tuner card and uninstalled that wondering if that was interfering, but no luck. So, does anyone have any new insights? I've gone through multiple forums and threads and know that other are having similar problems. But it also seems that several people have discovered solutions and has got it working. By the way, I have installed this camera on a Windows 7 32-bit machine and it works fine. Thanks in advance for any help to this extremely aggravating problem.