Have Windows Vista Home Premium fully updated. Trying to use a Celestron Digital Microscope which plugs into the USB port. I followed installation directions, the microscope was recognized instantly, and the software installed without problem. When I try to use it though, the software displays a message: "connecting to digital microscope" and then nothing ever happens. The software does know when the microscope is plugged in and when it isn't. The lights on the microscope light up but no picture is ever displayed. Have tried uninstalling, reinstalling from disc and from manufacturer's website - same thing. Have verified that I have the most current driver. Company shipped me another one but the same thing happens. Have tried two different versions of webcam software - ManyCam recognizes it but says that "the device is already in use with another application" even though I don't have anything else running. Have looked through various parts of the Vista Control Panel (device manager, application associations) and nothing seems to fit with this. Anyone have any suggestions? Thanks very much.