To make sure that your Internet Explorer is not trying to use dial up connection:
- open up IE
- click on "Tools" button in the tool bar in the upper left-hand side of Internet Explorer
- select "Options" from the menu that opens up
- click on the "Connections" tab of the "Internet Options" window
- put a "dot" in the radio button next to "Never dial a connection"
- click "Apply"
- click "OK"
- close Internet Explorer
- restart your computer
Now try using your explorer again - this time it should use your existing LAN connection.