Why is Internet Explorer telling me that the SmartScreen Filter service is unavailable?
When the SmartScreen Filter service is not available, websites you visit during that time cannot be checked against an online list of websites that have been reported to Microsoft. The service is unavailable if your computer loses its Internet connection. Make sure you are connected to the Internet and try again. If you are connected to the Internet but you haven’t updated Internet Explorer recently, you might have an older version that is no longer supported by the SmartScreen Filter service. To check for updates, click the Safety button, and then click Windows Update or download the latest version from the Internet Explorer 8 webpage.
