First, you may start with a default backup option enabled. Instead of starting with no backup set, assume your user installed the application to backup something, and start doing it with the most common option (Home folder?) let them know by starting the application in the backup places selection area (with the Home folder serected).

If you are unsure you can ask a question at startup, as below. Always stay in the user's perspective, not the software's ("I want to backup..", not "Choose a folder" or "What do you want to backup?"):


    ________________________________________________________________________
    
    I want to backup:
    
    [ MY WHOLE COMPUTER ]  [ MY HOME FOLDER ]  [ OTHER PLACES ]
    
    full protection,       Includes pictures,    More advanced options
    lot of space           documents, movies     Choose all the places you like
    
    ________________________________________________________________________

The [ OTHER PLACES ] button brings to the backup places selection area, where You should show the most common places/options. Note I keep calling them places instead of folders, you may find a correct term, not necessarily folder.



    BACKUP SELECTION
    ________________________________________________________________________
    
    I want to backup:
    
    [SWITCH]  [ICON][ MY WHOLE COMPUTER ] size
    [SWITCH]  [ICON][ MY HOME FOLDER ] size ( contains..)
    [SWITCH]  [ICON][ IMAGES ] size
    [SWITCH]  [ICON][ MOVIES ] size
    [SWITCH]  [ICON][ DOCUMENTS ] size
    [SWITCH]  [ICON][ MY DESKTOP ] size
    
    [ ADD ANY OTHER PLACE ] Choose or drag here any folder
    
    _______________________________________________________________________

This is backup for people that don't know about files, folders. and backups.., they just want to save "things" from "crashes".


One other fine extension might be, if you can search for the recently modified files on the device, you can actually see **where the user is working**. So if he/she doesn't even know where his/her files are, you do. You can propose those folders in the BACKUP SELECTION options list or warn him her ("I see you have not backed up folder yyyy where you have saved 12 files recently"). This can lead to privacy issues, as you do not want to ask him to backup folders like "xxx - Jenna Jameson - porn", so you may add a [` FIND RECENTLY USED FOLDERS ]` button to let him choose, or select them by file type .xls .doc, etc...