Earlier question along the same lines: https://support.mozilla.org/en-US/questions/923427

Thanks My system is Windows 7 SP1 fully updated with Norton 360 a/v My problem is as follows: Installed Firefox with no difficulty It opened normally Used and setup Google News UK as default page with no difficuly and page opened normally. But then trried to open individual items in Google News and every time got message Internet Explorer cannot open this site Set up a bare Windows 7 SP1 drive and installed Firefox and continued with same message when opening items on the page I also use both MSN and Yahoo browsers and neither have any problems I have repeated the process in Windows 8 beta with the same result Daniel

Daniel, apologies for the inconvenience, but your question sounds different to the one at the top of this page. Can you please start a new question and paste in your list of add-ons when you're filling out the form?