MintOS on W7 - Vbox can't find it

[himagain]

Hi guys,
I HAVE tried to solve it! :-{
D/L and converted Mint ISO to VDI but VBox reports:
"Fatal Error no bootable medium found. System Halted."
Had same problem trying to load Ubuntu previously.
Everything LOOKS fine and VB starts up then can't find the start file.
On the same system I have a very old (2years ago) install of XP in VBox. Still works.
Must be missing something simple!

Cheers!

I HAVE to install as Linux on Windows to be able to use Dragon voice-2-text in the Linux Vbox. ( Weird but true!)

[mpack]

D/L and converted Mint ISO to VDI

What on earth does that mean?

The proper way to use an ISO is to mount it in the VM as a virtual CD. Converting it to VDI is counter productive.