AHHH ROUTER HELP!!!

Ok, so i'm not exactly a techie type of guy, I'm not completely clueless when it comes to computers but I'm also not one of you guys who knows a computer like the back of his hand...so hopefully you can forgive me for the lack of a technical explanation.

So heres the deal, I've had a wireless network for years now, and over the course of those few years I've gathered a few routers. Recently my computer was unable to access the internet (out of the blue). So I disconnected the router and ran my cable modem directly into my computer, and after resetting the cable modem, I have no issues reaching the internet. So, I hook the router (at this point i've also tried resetting the router) back up and notice that when i plug the router into the NIC card it doesn't light up and my cable modem doesn't have the activity light blinking.

I decide the router is bad, and go and grab one of my other 3 working routers. I plug everything in reset the modem and the router and now the activity light on the modem is blinking, and the NIC card has a green light and a yellow light lit up. Neither are blinking, they just stay lit. When I plug the modem directly to the computer only the green light comes on...once i use the router i get a green and yellow light. The computer STILL won't access the internet through the router. My other computers which have never had an issue can't see the internet, and when searching for a wireless network they can no longer find one.

So now i'm thinking somehow my regular router is broken, this second router, despite the fact that i used it a few weeks ago, somehow is also bad. So i go and grab a THIRD router which I own. Same issue, no internet, green and yellow lights on NIC are lit, computer can't assign an IP address and will not access the internet.

Now i want to say it's the NIC thats bad, but how can that be if it works fine using the cable modem directly? I tried using different wires for both the router and modem in the event the wires were bad. Even went as far as using a different adapter for the routers. I reset all the routers and cable modem each time i hooked them up, even restarted the computer.
As i said, with the second and third router the activity light is blinking on the modem...and I have no clue whether or not the NIC always lit up green and yellow when the router was plugged in and was working.

Although I don't think this makes a difference based on the problem, the routers (all of which were working fine a few weeks ago) are different brands. 2 are linksys routers and one is netgear.

Any of you gentlemen who are smarter than me think you can lend me a hand, or some advice? I am so lost on this. Thanks.

Hello,

Have you tried using different cables between the cable modem, router and your computer's network interface card?

Have you contacted your ISP's technical support department to let them know you have switched routers and provide them with the MAC address for the new one (it should be on a label on the side or bottom of the router)?

Regards,

Aryeh Goretsky