I think I should add that the bigger HD (1TB) isn't empty and neither is it partitioned. I am somewhat concerned that to do a straight disk to disk copy, might result in lost data on the TB drive. As in the past when I've used Hd to HD transfer software I wasn't given the choice of placement other the intended HD. It seemed to assume that the new host disk would be empty.
Surface Pro 4 UK release date, price and specs: Thinner, lighter, faster with new Type Cover and Pen