I have a laptop I download many of my photos onto; it was a Windows 8 laptop and then it upgraded itself to Windows 8.1 and finally Windows 10. The trouble is, every time it makes an update, it changes the way it files new downloads. I had a bunch that just seemed to disappear - I couldn't find them anywhere - and eventually I discovered the computer put them in "Music". Stupid, but I should have caught it when I did the download.
One of these months I need to put everything back where it belongs.