The beta version of Service Pack 2 for Windows XP, issued late Wednesday, is available to registered testers for download through the MSDN developer site, the company announced.
As previously reported, changes in SP2 are focused on security. The update includes a reworked firewall component, now dubbed Windows Firewall, that will be turned on by default to protect PCs from outside threats.
SP2 also turns off the Windows Messenger service by default. Spammers have latched onto Windows Messenger--which is supposed to be primarily used by systems staff to send administrative messages to computers on a network--as a way to deliver unsolicited pop-up ads.
In addition, the update tweaks the Internet Explorer Web browser to block pop-up ads on Web sites and to prevent inadvertent downloads of software.
The service pack has a number of security updates aimed at preventing exploitation of "buffer overrun" flaws, an increasingly popular avenue for hackers to use in launching remote attacks on PCs.
It also provides more support for wireless networking and for short-range Bluetooth wireless connections, along with a new version of Microsoft's DirectX graphics library.
The first beta version of SP2 is aimed primarily at IT administrators, whose comments will help shape the final form of the update, according to Microsoft.
"The Windows XP SP2 beta includes a subset of the technologies that will ultimately ship in SP2, and the final feature set will be based largely on customer feedback generated during the beta process," the company said in a statement.
Microsoft has said it expects to have a final version of SP2 ready by mid-2004 for all Windows XP users.
Service packs typically bring together bug fixes and patches previously introduced in piecemeal fashion. Service Pack 1 for Windows XP, released in May, combined such patches with a handful of tweaks required by the settlement of the government's antitrust case against the Redmond, Washington-based software giant.
But Microsoft has been under increasing pressure to improve the security of its products, after a number of high-profile attacks this year. It has made security a key focus in the development of the next version of Windows, code-named Longhorn. But with Longhorn not due to hit the market until 2006, the company has to rely on Windows XP service packs to address immediate security issues.
