The items that are the same for all accounts either
1. are found in the All Users profile in Documents and Settings
or
2. are in each account's profile, possibly by their having been
copied there at first login from the Default User profile
This is so for start menu items or desktop items (you will see
two folders with these named. If something is in All Users but
you only want it for two accounts, copy to corresponding location
in profiles of those two account (copy - do not move) and then
remove from the All Users profile.
Wallpaper is not handled in this way as it is stored in the
accounts registry area.