It’s a case where you are using Internet Explorer as well as DSL connection but the problem is it tries to use the dial-up connection every time whenever you open the Internet Explorer these is caused mostly due to existing setting of the Dial-up connection and for these click on the Internet Explorer option and after that select the tools and got to options or else you can go to control panel and double click on the Internet options and search for the connections tab and remove the tick mark from the dial-up connections which you are not using at present but if you still want to the keep the Dial-up connections but you have to click on the Never dial for connection and after that click on the OK.
You should also check your LAN setting for any additional configuration. Further on check even your dialup settings which is below your Network configuration and you have to Right click on the My Network places and select the properties option and check for the necessary setting or else you can click on the Start button and select setting from the start menu and click on the Network connections and search for the advanced tab and enter the dial-up preferences here you can uncheck the My location box or check the disable autodial and click ok to finish and try to open the Internet Explorer