i create topic because of the picture..
it is made of two same windows at different moments : one shows the common copy windows...that disappears but the taskmanager is showing that hard drive is still working, that can be as long as one or two minutes if you have plenty of ram and a fast usb3 [ mine is recent and one of the less expensive of kingston ]
it is not very easy to spot this behavior , i am sure windows will not show warning if user restart his pc before end of copy...