Installing on Citrix VM

Attempting to install the latest distro onto Citrix VM, however every time we attempt, it fails and asks us to insert disk 1 of centos. Now looking over the install documents on Freepbx wiki, there is no mention of needing to download centos separately. This fails no matter which version we attempt to install.

VM is loaded with quad cores and 3GB ram, 20GB HDD Storage. This is just a testing environment for now with the plans to expand into full production.

Any ideas would be helpful.