Something is really hinkey
1) is there a
metadata.db in the indicated folder
2)What are the
user rights for that folder (and all child folders)? They need to have 'FULL' (read/write/delete/create)
Regardless of what the top line says. Use the first item to browse to the Library.
Maybe W8 does not like full rights to a Root folder
On one of my systems (xp) d:\users\Calibre Library
Just keep the first level name short