Have you ever tried to boot XP or Vista from USBP? Usbtuner does all for you! Microsoft doesnt support that functionality. From now on use e.g. your company computer/laptop at home without any risk! You can install what you want!!! Install Windows to an internal drive, run Usbtuner and connect drive to an external usb cable and it will no longer show you a bluescreen. The result is a very fast and optimized disk access even to the external drive! Almost no difference in performance compared to internal drives.