My Start Menu is Very Sick and I Don't Know the Cure

> I did some major damage to my Start Menu. Whenever I get a new computer (as
> I just did) I try to tidy up the Start Menu into logical groupings, e.g.,
> "Utilities", "Development Tools", "Imaging", "Audio", etc. In the past (98
> and XP) I used to go into file explorer and create new Start Menu folders,
> move items around, etc. Also, I want to make programs available to all
> users, not just the account which installed them. Well I tried to do this on
> Vista and I made a royal mess. Looks like I moved stuff around in
> "ProgramData\Microsoft\Windows\Start Menu\Programs\" and I have duplicate
> stuff in "Users\<myUserid>\AppData\Roaming\Microsoft\St art Menu". The upshot
> is that when you actual hit the Start Menu button, you see duplicate entries,
> some of them display submenus, some don't. The more I try to fix it by
> renaming, moving or deleting entries in the above directories, the worse it
> gets (e.g., in one case, there were 3 of the same entries!).
>
> Can somebody give me a) an explanation of the way the Start Menu works, and
> b) help me clean up the mess?
>
> Thanks, TommyVee