UTM Firewall virtual appliance - NIC not recognized by CentOS

We have dedicated one server with two NICs for UTM Firewall virtual appliance, but after clean boot with ISO image we have problems with NICs. One NICs is not seen by CentOS and network configuration file cannot be changed and we get read-only file system message.
Any idea how to deal with that?

Also, we are booting from USB and at the start we get message: Unable to download the kickstart file.

I will close this post by saying that we had to make bootable DVD instead of USB in order to boot the image successfully. I am not sure why this restriction especially when there is no warning about this limitation in installation guide.