ERROR CANNot install ubuntu 13.10 .............

[sairaj]

HI
I am using CENTOS 5.10....
I want to install ubuntu 13.10 on virtualbox..........
I have downloaded the ubuntu 13.10 iso file from its site
But i get an error ..........
DETAILS:
BASE memory 498 mb
BUT when i try to insert the iso file in controller IDE
IGET this.........
Failed to open the optical disk file /root/Desktop/sairaj/ubuntu-13.10-desktop-i386.iso.
Could not get the storage format of the medium '/root/Desktop/sairaj/ubuntu-13.10-desktop-i386.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)

WHAT SHOULD BE DONE???????
THANKS........................

[socratis]

Check the MD5, SHA1 or SHA256 sums as found on the bottom of the page you downloaded the ISO from. Maybe it's a corrupt download.