Where Windows 7 stores pinned files and folders

In Windows 7, programs, files, and folders can be pinned to the Start menu. (For files and folders, the way of doing so isn't super obvious: you have to drag them from Explorer onto the Start button.) Programs that are pinned get shortcuts placed in a certain folder under %APPDATA%, but file/folder pins don't appear there.

So, to find where that information goes, I did some digging with Procmon. I found that Explorer keeps the pinned items in the values in this Registry key:

HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\StartPage2

The values of interest are Favorites, FavoritesChanges, and ProgramsCacheSMP. They're all binary, so changing them would be difficult. I did manage to replace a pinned folder with one with the same length of name in the same parent folder by changing all instances of the original target's name to that of the new target, but adding, removing, or significantly modifying an entry would be very difficult without reverse engineering the blob format.

Based on my Super User answer.