Not a good day. Out of the blue all the devices on usb connections are suddenly not recognised. Except some. Very strange. And worrying. If I can'tconnect my Portable Media Centre every couple of weeks it will lock out all the protected content and none of my music will work. By a methodical process of investigating, careful use of restore points and experimentation with the hardware settings I've discovered that I've no idea what on earth is going on. Ah well, perhaps it is time for a fresh install.