extract (not deleted) files from driver

Recuva v1.40.525, win7

hi,

i'm tring to exract the files from a driver (external USB - 300GB) which are NOT deleted, but can't reach/open, due to a message saying i must format the driver before i can use it. i have had this driver for over a year, so i have a lot of files there.

When i do the scanning (deep scanning) i get a large list of files but i can tell is not ALL the files that i know shuold be in there...

so it found only a portion.

Does that mean theat it's impossible to find more file than what's been found?

can i run another scan (for the second time)? and when i do, will it:

add up to the list of the aleady found ones (frome the previouse scan) or start a totaly new one regardless?

any help will be appreciated.

Thank you,