Thanks but this did not work. However, this did:. Open Windows Explorer. Type or copy and paste the following into the address bar:%AppData% Microsoft Windows Recent AutomaticDestinations. Identify files that are comparatively larger in size than the rest of the file, such as files that have file size of 1 MB or more. Delete the bit file.
I already found out that the pinned items are stored under the following reg key in Office 2013: HKEY_CURRENT_USER Software Microsoft Office 15.0 Word User MRU%user Identifier% File MRU. Likewise for Excel and Powerpoint. However I was unable to find the location where the pinned items are stored within Office 2016. I had files pinned to my Excel task bar icon but now they are missing & I cannot pin any files. What happened? When I right click on the Excel icon, I can do one ot three things: Open Excel 2010, Unpin the program from the task bar or close all windows.
I deleted all of mine but then had to go back to Word, Outlook & such & repin what was there as this seemed to delete all of my pinned ites. Source link for more info.