maybe you know maybe not.. but
you have a backup of the 3 neigborhood on your hard disk, so if you wish to restore the original N00x hood just copy it
for example, on my computer the original files are stored in
C:\Programmi\EA GAMES\The Sims 2\TSData\Res\UserData\Neighborhoods(programmi = programs files, in english
)
so, you can open that folder and copy the N001 (pleasantview / bellavista, in italian version) and copy it on your
Documents\EA Games\The Sims 2\Neighborhoods