The last service pack for Microsoft Windows XP was released almost four years ago. In the meantime, engineers in Redmond were busy on a little project called Vista. Now that Vista has been out the door for a year, Microsoft has finished up Service Pack 3 for Windows XP and released it to manufacture. The new release will be available for public download next Tuesday, April 29.

“Windows XP SP3 bits are now working their way through our manufacturing channels to be available to OEM and enterprise customers,” Chris Keroack, release manager for Windows serviceability, posted to Microsoft’s TechNet forum. “We are also in the final stages of preparing for release to the Web (i.e. you!) on April 29th, via Windows Update and the Microsoft Download Center.”

SP3 will be distributed to home users via Automatic Update in early June, the company said. Online documentation for Windows XP SP3 will be updated next week.

The new service pack is a 70MB download to update Window XP and can be installed on top of either SP1 or SP2. It doesn’t work with the 64-bit version of XP, however.

Previous Patches

Much of SP3 consists of previously released patches, according to Andrew Storms, director of security operations for nCircle Network Security. “In terms of functionality, SP3 delivers eight mainline items, which had already been previously available by download,” Storms noted in an e-mail.

While consumers won’t notice much difference, “enterprises will welcome the added functionality of Digital Identity Management Service (DIMS) and support for WPA2,” Storms said. WPA2 is a wireless security solution derived from the 802.11e standard. DIMS allows users to access all their certificates and private keys for applications and services.

As for the new items in XP, enterprises will be mostly concerned with Network Access Protection, a platform that enforces compliance with network policies, and…