I do not believe there are any special drivers for the Pronto line. They are USB devices and "masquerade" as memory and disk. the windows drivers should be all you need and it should install them every time the Pronto is plugged into a USB port, and remove them when the Pronto is undocked. Are you plugging directly into the USB port on the PC or going trough some sort of USB Hub?
In the control panel system folder, hardare device manager. Under USB controllers, the Pronto is the composite device (memory+Disk)