You don't need specific software to set up Intranet as this is equivalent to LAN. If you have multiple computers, you need a switch with 4+ ports. You can assign IPs to computers starting from 192.168.0.1 up to the maximum number of computers ending in 192.168.1.X where X is the last computer. Make sure you also assign 255.255.255.0 as netmask and that's it.
