As of April 8, 2014, support and updates for Windows XP and Internet Explorer 8
are no longer available. Details can be found on the Microsoft website.
If you continue to use Windows XP(or older) your computer is vulnerable to security risks and viruses.
Using Internet Explorer 8(or older) can expose you to additional threats. As well it may not be able to display web pages correctly anymore.
Both are free, continuously updated and highly recommended.