If the 'Store independent databases for each PC user' option is on:
From version 7.5 you can create and use independent notes and address book databases for all users on your PC to ensure safe operation in multi-user environment.
This option is selected by default. A database for each user is stored in user's Documents and Settings folder:
for Windows XP C:\Documents and Settings\username\Application Data\MoRUN.net\Npp\
for Windows Vista C:\Users\username\AppData\Roaming\MoRUN.net\Npp\
If you need to have one notes database and the Address book for all users on your PC, you should remove the checkmark for the 'Store independent databases for each PC user' option in the Administrative tools.
If you remove the checkmark, your current notes database and the Address book will be copied to C:\Program Files\MoRUN.net\NotesPlusPlus (by default). This directory can be accessed by any user on your PC.
It can be useful. if there are several users on your PC but they all need to use the same notes database and the Address book.