Cannot delete folders

Just installed a my book 4 terabytes into a windows 7 64bit computer and after copying some folders into it I cannot seem to access them and cannot even delete them. It says error 0x80070091

Hi there and welcome to the WD community.

Try to check if you can change the permissions of the file or folders. By going to the security tab on the folder properties after you check the permissions check to see if you are able to delete the folders.

Here is a link that might help you out with setting the permissions on the folders:

Hope this helps.