'/sbin/ifconfig -a' returns:
lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU :16436 Metric:1 RX packets:1489 errors:0 dropped:0 overruns:0 frame:0 TX packets:1489 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:2499880 (2.3 MiB) TX bytes:2499880 (2.3 MiB)
'/sbin/ifconfig -a' returns:
lo Link encap:Local Loopback
Your system is not seeing your network cards. It is only seeing your loopback device.
I opened system->administration->network->edit->hardware device, and deleted the mac address from the box, and pressed Probe.
In less than 1 second it gave the correct mac address in the box.
Probe is not the reason your system has no network. What else did you change?