I am trying to fix a problem on a Windows 7 machine (which is not mine, so I don't know what it has been done on it, but it is in reasonably working shape and up-to-date with Windows updates and antivirus definitions).
The problem is that all pinned applications in Start Menu and Taskbar disappeared. If I pin any other application, it doesn't show up. The folders in
"C:\Users\USERNAME\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned" still contain all the shortcuts, so it's just Windows not showing them.
As suggested in this question, I tried deleting all shortcuts and putting them back, but it had no effect. Another source on the Web suggested that the cause might be a deleted registry key
HKEY_CLASSES_ROOT\lnkfile and suggested recreating it via regedit, but it is already there.
Edit: There appears to be more than that: apparently user settings are not saved, as I set up Firefox as the default browsing application but it keeps asking me that every time it is started. According to this article in the MS kb, it might be because the current user is not member of the workstation's group Users. I fixed this but it didn't resolve the problem. BTW, the current user has Administrator rights.