Firefox browses IE won’t

Windows Vista. IE will not browse any sites. It starts then stops loading the site as if it has lost the connection. (which it hasn’t). Firefox works perfectcly. I have done all I can think of. System restore. Removed security updates, set all settings for IE back to default. Stopped any firewalls. But to no avail. In vista you seem to have little control over IE. I cannot even browse the net using IE with no add ons. I get the feeling it is because of a change of ISP it seems to want to use the old dial up instead of the new router. Though I have set it to never dial a connection. Is there anything anyone can suggest to fix this issue?