How to remove recent authors entries that show up as soon as you start typing in windows explorer on .docx files?
Click on the "Authors" entries in Explorer to enter into Edit mode
Press and Hold Backspace key to remove all names
Press click "Save" button at the right side of the explorer pane.
It should do the job.
From what I can tell, the list is populated from ANY author on any file on your hard drive. You will need to find those files and delete the name of the author that you no longer want to see from those files properties. I had a problem where a name was popping up that I too no longer wanted to see, I had to track down the individual file and change its properties, now I no longer see that name.
Just search your files and filter by "authors" in explorer.
Hope this helps.