HELP! Basically.

I have been trying to recover some deleted holiday photos but I have come to a slight problem.

Recuva can see the files, but none of them have a name. hen I click on the little green dot next to a file then it shows me a preview of the files. So I know they are their, but when I tick the boxes (and their are a lot of them) and click recover all of the files get the error message "Access is denied."

I have tried changing the permissions on the external HDD, but have had no luck.

Can anybody make any suggestions?