Can not access internet

My second older computer today can not access the internet anymore. I have done the steps about turn off everything and turning them back on a certain order and still nothing. Its not the cords since I have plenty that work and tried most of them. The computer reconizes that it connects to the router, but when I open firefox, it has a problem trying to get to any website.

I'm thinking that the card inside the computer has gone bad, or there is extreme amount of dusk inside and I should just clean it out? Anyone's opinion?

 

Well, if your computer is dirty on the inside, cleaning it is always a good thing to do, even if it does not solve the current issue. Be careful about ESD (electrostatic discharge) when working or cleaning inside your computer.

Did this problem just start today, all of a sudden? Are you using an onboard LAN port or an add-on LAN/Ethernet card?

 

sorry I forgot to reply earlier. We cleaned it out and did a system restore for a week. It now has internet.