This type of error often occurs (and not just with Prontos) when 3rd party drivers for another USB Human Interface Device (usually keyboard, mouse, touchpad, graphic tablet) have been installed. Badly written 3rd party drivers can interefere with other HID device detection or driver loading. Hence it's often note the fault of the manufacturer of the product in quesrion (in this case Philips), or Microsoft, but another vendor altogether. Similar problems occur with wireless cards, 3G cards, etc.