Hi,
When connecting an external drive to a Windows computer, sometimes the permissions/privileges will need to be assigned. Since the ownership of the files belong to a different user account, you may see "Access Denied" or "Not accessible" errors when trying to open the drive or a folder within the drive. To gain access to the drive, kindly follow the steps provided by Vijay B on this link.
If you require any further information, feel free to let us know.
Regards.