If the link does not work fine, but in FF in IE, which is indicative of or a new installation of malicious software, they click the IE browser for the proxy server settings such redirected elsewhere.
If you have attached IE8 plugin, you should be banned because they are lost or wrongly.
You can also download and install Malwarebytes Anti-malware. This is a free download, in my experience that doing good work or to find a child or malicious software.