After my many re-installations of Windows 7, I often have an “Unknown Device” in the list of USB devices shown by the Windows Device Manager. It is almost always because of my LogiTech G110 keyboard. It works as a USB keyboard with no additional setup after these re-installations, but its extra functionality (like the cool lighted key caps) require that the device driver be installed. Doing so invariably removes the last “Unknown Device” warning from the device list.
Ever since the purchase of a nice new system running Windows 7 Professional, I have been plagued by periodic system crashes. Crashes that make the system unstable and that finally make it unbootable. And it’s all the fault of Windows Update.