If your computer is already connected to the Internet, but you need to configure your browser to use the proxy server, follow independently the process. When using the Internet browser Opera, press Ctrl and F12 after starting it. Select the "Advanced" tab in the menu.
Look in the left column menu "Network" and open it. Click the "Proxyservers"located at the top of the window that appears. Activate the "Configure proxyservers manually" by selecting the check box near the appropriate text boxes. Now select the protocols you want to use to access the Internet through a proxy server. Enter the IP address of the server and specify the port to connect to. Click "OK" and restart the Opera.
If you prefer to use to access the Internet program Mozilla FireFox, start it and navigate to the settings menu. Usually this requires opening the appropriate tab. In the menu that appears, select the tab "Advanced". Now click the "Configure" button located in the paragraph "Connection".
Select the check box next to the option "Manual proxy configuration". Configure the desired protocols, as described in the second step. If you need to access specific resources without using a proxy server, enter their addresses in the field "No proxy for". Save the settings by clicking "OK".
To configure Internet Explorer, start it and open the "tools" tab. Select "Internet options". Open the tab "Connections" and click "Customize" located in the "configure remote access".
Check the box next to "Use proxy server for this connection". Enter the desired address and save the browser settings.