Don't know if any of these are any use
Backup Mounted Volume NV-U73T
Look here also,
For other pna's to restore to Sony software again if you deleted all by accident, try this, thanks nukka
Restore the folder Mounted Volume\Sony\Bitmap from one of mounted volumes backup, because this one is not in the Sony update.
(The bitmaps are only different depending the size of the screen.)
Update the last version of your pna with the software of Sony Website , 3.
Put a map in the mounted volume\Sony folder.