wired network not working

[mayank123]

I recently install lubuntu in my old system. but It cannot connent with wired connection I can see A device MAC address as 00:00:00:00:00:00(eth0). When I select it save button gonna disable. I cant figure out what and issue I am newbie so not much knowledge about issue but I think my system is too old so lubuntu cannot recognize NIC.

[Iowan]

What is the system - ethernet card in particular?
(That doesn't look like a valid MAC address)
Could you post results of sudo lshw -C network and ifconfig -a
(those commands would be issued from a terminal)