Now and then I used to come in touch with a PC (a laptop) of a friend of mine. This PC used to display a rather strange behavior. This PC, running Windows 7, would not correctly mount any usb hard disk or pendrive, except for a few new USB 3.0 drives. This Asus laptop had a really convoluted installation history, as even specifying the precise model it is not very easy to uniquely determine the specific driver to install for a given device. It turns out that every re-installation is made is a sort of trial-and-error procedure and the final outcome is, as one can see, not very nice.