Router/modem problems

[Dopey]

Hej guys!

ive just installed an wired router. Ive connected all of the wires. But my I-Mac just doesnt want to connect to the internet but my macbook does.
Ive put the exact cable in the imac first (to discover that it doesnt connect with internet)
But when i put the same cable in my macbook it doesnt connect to the internet.

BUT!

When i plug both the Imac and the Macbook i can connect with each other. So there is nothin wrong with the cable.. but what the hell is wrong...?

Please explain and tell me the solution!

Thanx in advance!

 

[earthsaver]

Modems remember what device they're connected to until you reset them. When you disconnect the Ethernet cable connecting modem to Mac from the Mac and moved it to the router, you need to power-cycle the modem to refresh its connection and associate it with the router. Then, you should have no trouble connecting any computer to the router.