Microsoft has released to manufacturing (RTM) its Service Pack 3 (SP3) update for Windows XP, and said it intends to make this available for general download on April 29th. Distribution via its Automatic Update service will come later in the summer.

In a statement, Microsoft said that SP3 includes all previously released updates for the operating system, as well as a small number of new additions that should not significantly change the Windows XP experience. However, it does not include the Internet Explorer 7 browser.

One notable new feature is support for Network Access Protection (NAP), a technology that was introduced in Windows Vista and Windows Server 2008. NAP is a policy enforcement mechanism with which firms can protect their network by ensuring compliance with system health requirements. NAP has been included in SP3 to make it easier for firms to manage a mixed environment of XP and Vista clients using Windows Server 2008, according to Microsoft.