The Comodo Internet Security v7.0.3 bootable CD/DVD rescue disk maker calls for the user to optionally select the rescue disk ISO file if it has already been downloaded, otherwise it will be downloaded from the Internet, select the target drive, then click on Start.
In my case CIS does not download the rescue disk ISO from the Internet nor can it identify the target drive.
I successfully downloaded the Comodo Rescue Disk 2.0 ISO with Firefox and burned it to a CD with CDBurnerXP. The resulting rescue disk seems to work properly though I am uncertain it is the optimum ISO for CIS.