Create image of external USB HDD

Hi.

Most of the articles I found with external, USB and HDD are people trying to create an image on to their external HDD. My scenario is a little different.

One of my old servers died a little while ago (mobo died, HDD is OK). Rather than putting it into some new hardware, I am tinkering with VMWare ESXi.

I have plugged my existing HDD into a USB device and can access it as a normal HDD.

I want to create an image of that external HDD (to a .tib file) so I can create a VM of my old server.

Doesn't matter what I do, my version of Acronis TIH V9 won't allow me to 'add' or 'backup the entire disk' of my external USB HDD.

I have checked options etc but cannot find anything related. Any ideas?