I want to change my OS ( ubuntu 16.04 with unity desktop) from 32 bit to 64 bit.( I have checked that my PC can run 64 bit programs ) I have a lot of material which I have saved over years and I don't want to lose it . I have a second internal dsc and an external disc connected by USB. I would like tto put the material I wish to keep on the external disc , My PC has several usb sockets and I have previously used them to write files to USB memory sticks. This was an easy operation because when a usb stick is put in a socket an icon appears in the desktop launcher . When this icon is clicked the contents of the stick are shown and files can be added by dragging them to the contents area. I would like to use the same method to transfer files to the external disc connected by USB. Is it possible to do this? At present I have no way to display the contents of the external disc connected by USB.