I can connect to my home router (Vigor 2700VG) wirelessly from my laptop but I can't connect to it via the cable - from either my PC or laptop. Trying the Win7 network repair it just says cannot renew IP address.

Tried 2 further known working cables.
Reset router to factory defaults.
Tried putting in IP addresses manually.

The desktop is a new build (network port on the motherboard stopped working) and that won't connect - I thought the network port on the old board was not working but now I'm having issues with the router I'm not so sure. The network port lights on the board didn't work and Win7 said no network adaptor.

The machines both register the cable is plugged in but thats it. When the machines do connect over the wired cable, the green port light on the router just flashes constantly twice a second or so until the machine is turned off or the cable unplugged.

Tried turning everything off for a hour but no luck.

I'm completely stuck here.