я пытался установить Ubuntu на виртуальный ящик в Windows 8.1 и получил ошибку

Failed to open the optical disk file D:\programm setups\ubuntu-14.04.2-desktop-amd64.iso.

Could not get the storage format of the medium 'D:\programm setups\ubuntu-14.04.2-desktop-amd64.iso' (VERR_NOT_SUPPORTED).

Result Code: VBOX_E_IPRT_ERROR (0x80BB0005)
Component: Medium
Interface: IMedium {05f2bbb6-a3a6-4fb9-9b49-6d0dda7142ac}
Callee: IVirtualBox {fafa4e17-1ee2-4905-a10e-fe7c18bf5554}
Callee RC: VBOX_E_OBJECT_NOT_FOUND (0x80BB0001)