Hi folks completely new to this and never grew up with computers. Have just bought a Microsoft Surface and wish to add an external HDD. I was told to buy an external HDD with its own power supply not just through the USB. I understand the principal but can not find one to buy. Any advice please. Need about 1 TB or maybe 2. As I live in country Australia I can't pop down the local store - there isn't any, and I will need to buy from Ebay or similar. Thanks in anticipation. As I am 64 and never grew up with computers please don't bombard me with tech speak. Just the basics will do this struggling computer user! Thanks heaps.