All of the files that I have deleted over the last 4 weeks have reappeared, no matter what kind of file. Are you saying that I should uninstall the reader ??
Video files are opened using VLC media player.
I note that the problem only occurs with files from Drive C, files deleted from drive F (another fixed drive) delete OK and stay deleted.
I will try moving some files from C to F and then deleting them, to see what happens with the drive C files.
Also I noticed a little while ago that the drive C icon now has a "Microsoft flag" superimposed upon it.