Error Boot for Ubuntu

[KingVV]

I have installed VB in Windows 8.1 for use Ubuntu 13.10 64 bit.

I have a problem ... Fatal: no bootable medium found! System halted.

My configuration:

IDE Master Primary: ISO Ubuntu
IDE Master Secondary: DVD Image Ubuntu

Boot: 1) HD 2) DVD

My PC is ASUS N750J

Help me ... thanks.