If you need to add a program shortcut for all users - after installation - if you open the start menu and click on all programs.
Right clicking on a folder should present Open & explore options - to edit the active user's start menu and also "Open all users" and "Explore all users" entries to edit the start menu for all users
As there is not always a dual copy of folders I would suggest you right click on the startup folder entry
Note that you will probably see UAC prompts when copying/Moving shortcuts into the All Users area
the actual all users folder is at
Hope this helps