I recently ran into an issue with a pinned Excel 2016 document that wouldn’t go away. I’d pinned it to the Excel jump list (on the Windows 8.1 task bar) and despite clicking the ‘Unpin from this list’ icon next to the document itself, it was well and truly “stuck”.
I tried simply unpinning the Excel icon from the taskbar but that didn’t help. I installed Windows and Office updates and rebooted but the document kept appearing.
A bit of searching led me to the AutomaticDestinations folder, which can be safely (?) cleared from a command line like so:
del /F /Q %APPDATA%\Microsoft\Windows\Recent\AutomaticDestinations\*
Copy or type the above as one line into a command prompt.
Note this is likely a hidden folder but despite having Explorer configured to show hidden items, I couldn’t see it within the Recent folder.
This command comes from the tutorial (option 3) at https://www.sevenforums.com/tutorials/81483-jump-lists-reset-clear-all-items.html, which also contains a second delete command for CustomDestinations and suggests logging off/rebooting for full effect. I didn’t need to run this second command or reboot. You may find it helpful if the above delete command doesn’t work on its own in your case.
It’s important to be aware your pinned jump lists for other applications will also be cleared, included Explorer.