unplug your usb device\cable
click start and type
click on device manager
look for unknown device or somthing to that effect with a yellow question mark right click on it and select uninstall
reconnect and windows will try to reinstall it.
you may need to install the driver software first what type of camera is it?
are u on 32 bit or 64 bit
not sure? press the windows key and the pause break key at the same time to check.http://support.microsoft.com/kb/126449