QuickCam is the name of the drivers logitech use for their webcams. QuickCam 8.4.8 is the latest version.
From Logitech site:
"You must have DirectX 9.x or higher installed prior to installing this software.
This is the latest software release for most tethered cameras and the QuickCam Cordless camera. This software makes it easier than ever to do the things you want with your camera. This is a full version, but does not contain any third party applications to minimize download size.
This release adds support for the QuickCam® Communicate STX, QuickCam® Notebooks, QuickCam® Notebooks Deluxe and QuickCam® Chat cameras."