On Friday, Microsoft finally released Windows XP Service Pack 2 (SP2) to manufacturing. The release marked the end of a year-long struggle for the software maker. Last summer, Microsoft abruptly decided to retreat from its original plan to ship SP2 as a simple collection of bug fixes. Instead, the company recast the release as a major security update with numerous new features. But Microsoft continually delayed XP SP2, largely because of incompatibilities caused by radical changes in the way XP now works.
  
"Final testing is complete, and at 10:08 A.M. [Pacific time, Friday] morning we signed off on build 2180 as Windows XP Service Pack 2, releasing it to manufacturing," a note to beta testers said. "The final build will be available to beta sites immediately. You will find both English and German versions there; Japanese will follow early next week. Next week, the service pack will be available on the Microsoft Download Center for general download."
  
Given the long wait for XP SP2, you might be disappointed to discover that the final release isn't yet widely available, but that plan is by design. Because hundreds of millions of people will want to upgrade to this release, Microsoft is staggering XP SP2's availability. Beta testers--the first users to receive access to the release--quickly knocked Microsoft's beta Web site to its virtual knees Friday morning under the weight of their connections. On Friday afternoon, the company provided a version of XP SP2 to Microsoft Developer Network (MSDN) Universal and Professional subscribers through the MSDN Subscriber Downloads Web site. 
  
Tomorrow, Microsoft will slowly start shipping XP SP2 electronically to XP users who have enabled Automatic Updates. Microsoft says that the size of the Automatic Updates download will vary based on how up-to-date your system is. A typical download will weigh in at about 75MB, but users who upgraded to XP SP2 Release Candidate 2 (RC2) will have a download of less than 30MB. Microsoft expects to deliver SP2 to more than 100 million users through Automatic Updates. Later this month, the company will distribute SP2 as a critical update through Microsoft Windows Update.
  
XP SP2 will be the subject of a massive marketing campaign as Microsoft attempts to get the update into as many users' hands as possible. The campaign will include free SP2 CD-ROMs, both through Web orders and at retail stores, and an effort to get retailers to update already-stocked XP machines to SP2. PC makers will begin shipping new PCs with XP SP2 in the next 6 to 8 weeks. Microsoft also intends to deliver more than 25 localized versions of the service pack during the next 2 months.
  
So what's the big deal with XP SP2? Despite its service pack moniker, XP SP2 is nothing short of a major new version of Windows. The only real difference between this release and a full Windows upgrade is that SP2 concentrates almost exclusively on security updates. "SP2 is a significant step in delivering on our goal to help customers make their PCs better isolated and more resilient in the face of increasingly sophisticated attacks," Microsoft Chairman and Chief Software Architect Bill Gates said. "It is the result of sustained investments in innovation and extensive industry collaboration. It also reflects a broad recognition that as the security environment changes, the industry needs to respond."
  
XP SP2's security updates concentrate on three key areas. First, the product features stronger base security settings than the initial XP release, including a variety of technological changes designed to protect users from broad types of electronic attacks. Second, XP SP2 provides new and simpler security-management tools, for both end users and administrators. And third, SP2 includes several updated components, all of which are designed to offer better security than their predecessors. These components include a new wireless client, Bluetooth support, and new versions of Microsoft DirectX and Windows Media Player (WMP).
  
XP SP2's changes are so drastic, in fact, that Microsoft acknowledges that certain applications and services will experience compatibility problems. For this reason, businesses should thoroughly evaluate SP2 before rolling out the update. But make no mistake: All XP users, whether they're individuals or corporations, should upgrade to XP SP2 as soon as possible. As Microsoft representatives note, SP2's more secure environment will more than make up for any potential incompatibilities.
  
I've written extensive articles about XP SP2 on the SuperSite for Windows and will update the site this week with new articles about deploying and slipstreaming the product. For more information, visit the SuperSite for Windows Web site.