Some applications may vary how and where they store the MRU (most recently used) file info. For example Wordpad maintains it's internal list in the registry under HKCU\Software\Microsoft\Windows\CurrentVersion\Applets\WordPad\Recent File List, this only applies to the recent files when you open Wordpad. A seperate taskbar pinned icon list is maintained in a database type file you can't really manually edit. It is located in C:\Users\<username>\Appdata\Roaming\Recent\Automatic Destinations\<GUID>.automaticDestinations-ms. The easiest method for adding your recent documents etc is to simply open them all up. That should add them to the pinned icons right-click menus.