Unable to Delete a File?

Here's a tip from Matt Currey, "...create a new folder on the desktop, put your mystery file inside this folder. Now, create a new, say, simpletext document. Save it on the desktop with the exact same name as your mystery file. Now move it into the folder in which your mystery file is sitting, MacOS will ask you if you want to replace the file already in there with the same name. Say yes! That should work...." [It did for me!--Bill]