How to Fix a Computer That Won't Connect to the Internet
Internet connection issues can be mysterious in nature. Connection problems can seem to appear at random and with little or no warning. Because there are so many possible causes, fixing the issue requires a process of elimination through troubleshooting. The process is useful to fix a computer that will not connect to the Internet.
Ensure that the website you are trying to reach is not the problem. Use a large website such as Google or Microsoft, putting their full website address in the browser's address field. If you are able to reach one of these websites, the problem is with the website you were originally trying to reach (see Reference 1).
Check the browser's configuration, disabling any proxy options that may be set up. From the Windows Start menu, open the control panel. Select Internet Options and then navigate to the Connections tab. Click the button labeled "LAN Settings" and uncheck the box under Proxy Server. Click "OK" to apply the new settings (see Reference 1).
Confirm that your network router has Internet access. Open the router's web configuration page from the browser. On the main page, the router displays an Internet connection status. The status should show a healthy and functional Internet connection. If the status shows otherwise, try restarting the router and modem.
Verify the computer's permissions on the router. From the router's configuration page, navigate to the security section. There should be a subsection for restricting a computer's Internet access. If there are any computers in that list, remove them, and then save the new router configuration. Try the connection again once completed.