hey man it very easy there are two ways
plan A
install the driver from the origial disc just for xp
the plug in your camera and vista does the rest of the work for you becasuse it update it
Plan B
use this driver wich is the same it work for many OS
http://www.driversreal.com/ezonics_ezcam_iii_usb_driver_windows_2000_xp.htm
Mexican, June 2008