In what's being called the death of Windows XP, Microsoft will no longer provide support for the operating system beginning today. Without Microsoft's security updates, computers running on XP will be left vulnerable to viruses and cyber attacks. That includes many of the nation's ATMs and small businesses still running on Windows XP. Microsoft is advising that XP users upgrade their current PC to run on Windows 8.1 if possible. If not, Microsoft encourages users to shop for a new computer.