just a quick NIC question

I have a pc with 2 NIC's at the back of pc out of the 2 lights on nic's is one supposed to be on permanently, one flashing slowly, quickly or intermittently?
cos i keep losing connectivity and its doin my head in

 

For NICs with 2 LEDs, one is the link light. If there is physical connectivity, this light is on. If it isn't on, then there's a problem with the electrical signals travelling across the wire. Either one of the NICs on either end is bad or the cable is bad.

The second LED is generally either a 10/100 light (it's on if the connection is 100, it's off if it's 10) or a network activity light (flashes when there's network activity).

 

Thanx guys, reckon its a problem with the cable wires from 1st pc to 2nd pc.My Standalone modem has 4 lights power constantly on, pc flashing quickly, data flashing occasionally and cable constantly on, but on one of the nic's on light is on, the other flashes when it wants, but i generally can get online, the 2nd nic one light is on and the other flashes occasionally and i can get online then lose my connection. Could i ask when i check my network connections should i see 2 connections on the pc that connects directly to the internet or 3? and on the second pc that connects to the internet via the 1st pc how many connections should i see in network connections i can only see the nic thats connected in the pc, not the gateway connection.
hope that makes sense.
Nicky

 

my upstairs pc now shows 2 connections, the nic in the upstairs pc and the gateway connection, but it still wont connect to the internet? any ideas? ive checked the Nics down ere and they seem to be workin fine