How to troubleshoot for a linksys router that won't connect to the internet?

The linksys router is wrt54g. I pulled the internet cable out of the router a few weeks ago and put it directly into the computer, and have been using wired internet since. Now, I want to use my laptop in other parts of the house again, but I cannot connect to the internet. The computer can connect to the wireless itself, but the router is aparently not receiving the internet or not sending it to the computer.
The modem and cable are fine to my knowledge.

How come my internet works with only these?

I cut open my internet cable and there are many colors. The only ones I wired together though was the orange and green. My internet works fine for years. I never bothered to put the other ones together because my internet is working perfectly. What are the other cables for?

What would cause my wireless internet connection to vary in speed and signal strength?

So I have a Dell and connect through high speed internet cable, broadcasting wireless through the house. When I log on, the speed is usually very low (24 Mbps) and the strength is low. Eventually it makes its way up to 56 (?) Mbps and a Very Good signal strength. Is this my issue with the computer/wireless or an issue with the cable company? It’s very frustrating.

How can I get my computer to connect to the internet?

So right now I’m using my laptop, but my other desk computer won’t connect to the internet, and I don’t know what is wrong with it. So when I connect the internet cable to the CPU the send and receive lights just won’t turn on. When those lights are on it means that its connected and it get internet connection. I am sick of this laptop its a mini laptop and I just like my other computer’s bigger screen. How can I get it to connect to the internet? Its just not working. Thanks.

How can I make my wireless internet faster?

I have a lynksis router. Its okay but the internet is not very fast and it often loses its connection often.
My room is in the basement so running a internet cable (which is what I would prefer) isnt an option.
Any hints to help me get a better connection, faster download speed, and overall a more reliable network connection?

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