Here's how to make a Logitech Quickcam Orbit/Sphere webcam work with Vista

After a few hours I managed to make my Logitech Quickcam Sphere/Orbit webcam
work with Vista. Depending on your system, not every step below is needed.

First of all, install just the driver, not the complete software package
(qcq*.exe). To get to the driver, run the installer of the software. Then
pause it before letting it run. At this moment the installer will have
created a Drivers folder in Program Files\Logitech\Webinstall (this may be a
hidden folder). Now copy the Drivers folder to another location. Then cancel
the setup procedure.

Now connect the webcam. The New Hardware Wizard will ask for a driver, point
it to the copied folder. The driver will now install. Restart Vista.

Now go to Device Manager, the webcam will be listed under Imaging devices.
Click Properties and assign more bandwidth to the camera and delete the
checkmark at Autom.bandwidth. Maybe you need to restart.

After this my webcam now works, f.e. with Skype.

Succees!