Microsoft sends security update to home PCs

The first computer owners to get Windows XP Service Pack 2 began receiving it on Wednesday night, Microsoft said. The update is being sent to people who have the automatic update feature turned on in the operating system. But it will take at least a few weeks to deliver the 80-plus megabyte patch to the installed user base, a company representative said on Thursday.

"By October, everyone who wants it will have had the chance to get it," the representative said.

Placing SP2 to the Windows Update service is the final step in Microsoft's introduction of the security patch. The company had delayed distributing the update through the automatic process so that companies could block the patch until after they had fully tested it. Microsoft has already listed some applications that are affected by the new software.

While some security researchers warn that flaws have already been found in the update, the SP2 patch promises to boost security for Windows XP users.

Microsoft says the update adds better security to Windows XP's handling of network data, program memory, browsing activity and e-mail messages, by changing the system's code and configuration. A revamped firewall, for example, attempts to prevent malicious applications on a PC from connecting to the Internet by requiring that the user give specific permission for each attempt.

The SP2 software, which took almost a year to develop, is seen by many as a response to the attack launched by the MSBlast worm on Aug. 11, 2003. Almost 26 days before, Microsoft had issued a patch for the security hole exploited by the worm. However, many people did not install the fix, even though there was widespread expectation that a virus would be created to take advantage of the flaw.

Microsoft plans to cap the number of home PCs updated each day so that demand for the update does not overwhelm its servers, the company representative said.