I have been using a Western Digital MyBook 750GB external drive off of my DishNetwork DVR for awhile now. It is full. I disconnected the MyBook from my DVR and connected the same USB cable to my PC to try to offload some of my movies/fights to my PC. My computer will not recognize it. My machine is running Windows Vista. I tried on my wifes machine which is running Windows XP and my laptop running Windows XP still no luck??? Help I am out of space......