The hard drive needs only to be a 1GB drive.
You will need two Legacy Network Adapters. Remove the default created Network Adaptor, as Vyatta will not recognize it, and install two Legacy Adaptors. One should be connected to the external network, and the other willbe connected to the Private Virtual Network.
Insert the Vyatta ISO into the CDROM and start the Virtual Machine.
At the login prompt, type the login user and password. Both are vyatta.
Type Install-system to begin the installation.
Answer most of the next few questions with the default answer.
You have to answer Yes to the confirm format of the drive.
Press Enter to copy the default configuration file to the system.
Type in a new administrator password of your choice.
Eject the ISO and it is all ready to go.
The next part will take you through a basic and quick set up to configure the system as a router and basic firewall.