My laptop has win. 7 os. I tried unsuccessfully to boot win7 from a external usb hard drive. I have given up on that idea because of bsod. Now however, when I try to boot only from the internal hd it gives me a choice of which hd to boot from the phantom disconnected usb drive or the internal drive and I have to now always select the internal drive. How can I fix it so that it will automatically start from the internal drive?