Computers around the world have been shut off from the internet by Microsoft's latest security update kb951748. Microsoft has issued kb951748 as an update to fix a DNS (Domain Name System) security flaw on computers running Windows XP, Windows Server 2003, and the client side of Windows 2000 Server. However, Microsoft security update kb951748 does not play nicely with the popular firewall security program Zone Alarm. Zone Alarm is a highly regarded internet security program designed to protect computers from unauthorized access, viruses, and other malware that may be encountered on the web.