From this, it appears that the USB drivers are working fine, and it is a problem with the LifeCam applicatoin itself.
Regardless of whether the camera is already plugged in or is plugged in at that point, the remnants of the install process and the MS LifeCam application itself don't recognize when it is plugged in even though Google's messenger does. After every boot now, it pops open the window from the install process about positioning the WebCam which after closing prompts to plug in the camera. The LifeCam application says no camera is installed, but other messaging applications see (& operate) the camera just fine and it appears with no errors in the device manager. I'm having the same issue with the VX-6000 LifeCam under Vista. After this webcam should work and Microsoft LifeCam application should detect it in the first USB port which did not work before, which was saying "There is no camera connected to this computer". 6) Now chnage the USB ports again, wait until it's succesfully installed in the system saying Ready to Use. 5) Now do exactly the same things as described in step 1) and 2).
4) Wait a lil bit until it's succesfully initialized in the system. (as well can leave the drivers in the system, no need to delete them) 3) Now unplug webcam from Not Working USB Port, wait few secconds and plug into working one. (no need to delete drivers from system, can leave them installed) 2) Now search for Sound, video and game controllers -> Microsoft LifeCam NX-6000 and Uninstall. 1) Open Device Manager and search for Imaging devices -> Microsoft LifeCam NX-6000 and Uninstall. With LifeCam NX-6000 connected in the Not Working USB Port. Oh no, I made it!!! I post my solution here, it maybe helps the others.