"To continue receiving security updates for Windows, make sure that you're running Windows XP with Service Pack 3 (SP3). The support for Windows XP with Service Pack 3 ends April 8, 2014. If you’re running Windows XP with Service Pack 3 (SP3) after support ends, to ensure that you will receive all important security updates for Windows, you need to upgrade to a later version, such as Windows 8."
The better to receive security threats aimed at later versions of Windows, I assume.
If I were at all a geek, I'd go to Ubuntu, but we had it at work (installed for casual use by a geek parent) and no one knew how it worked. Eventually it crashed completely.