Firstly, perform a full system scan using your antivirus program or a utility from Software Informer database. After that, go to Start > Control Panel > Uninstall a program > Turn Windows features on or off, un-check the box next to Internet Explorer and click OK. Reboot your computer and enable again the browser using the Turn Windows features on or off tool. If you still have issues, try to remove all Internet Explorer add-ons using Remove Toolbar Buddy. Also, I recommend you update the browser to the latest version.