One of my HR20s' 1TB hard drive(installed inside the HR20) is full. It started to make this weird grinding sound, which probably means the hard drive is going bad. I plan to get another 1TB drive and copy everything before I send the bad drive in for replacement. How many hours will it take to copy a full 1TB drive to an empty 1TB drive? (using a PC) I realize it's not possible to get an exact figure... I just like a ballpark figure on the number of hours... Thanks!