How did you confirm that the connection is working? Do you have a Web Proxy set up in System Preferences/Network/Advanced/Proxies?
Check your DNS settings. System Preferences -> Network -> Advanced -> DNS -> DNS Servers
Make sure you have valid DNS servers like 8.8.8.8 and 1.1.1.1.
I have checked Advanced, then Network, and then I selected Connections. In Connection settings, it gives me options for configuring proxies. Am I in the right area to check? I do not have a DNS option under Advanced.
Have you rebooted your modem/router and your computer ?
Yes. If you use one then make the adjustment otherwise leave it alone.
Cable system internet usually make infrastructure changes on holiday weekends.
Turn on and off your cable modem. The firmware will be downloaded. then reboot your router and finally reboot your computer.
Intermet connection has been tested and works fine but when attempting to use webrowsers, Firefox, Safari, and Chrome wont work. When I try to pull up a webpage, I get the message 'Server not found'