Windows XP Service Pack 3 (SP3), due in the second quarter of 2008, will be the final XP service pack , according to Microsoft. Here's what we know about Windows XP Service Pack 3:

1. What are the supported operating systems for XP SP3?

Windows XP; Windows XP Home Edition; Windows XP Home Edition N; Windows XP Media Center Edition; Windows XP Professional Edition; Windows XP Professional N; Windows XP Service Pack 1; Windows XP Service Pack 2 and Windows XP Tablet PC Edition. But only the 32-bit versions of the operating systems enumerated above. And also only XP SP1 and XP SP2. Microsoft no longer supports the RTM version of XP, and this rule is also valid for XP SP3.

2. Is Windows XP x64 supported by XP SP3?

No. XP SP3 is addressed exclusively at the x86 versions of Windows XP. In the first half of 2007, Microsoft serviced both Windows Server 2003 and Windows XP Professional x64 Edition with the release of Windows Server 2003 SP2.

3. Is XP SP3 an equivalent of Windows Vista/Vista SP1?

No. In the company's own words: "Microsoft is not adding significant functionality from newer versions of Windows, such as Windows Vista, to Windows XP through XP SP3."

4. Is XP SP3 a repeat of XP SP2?

No. Service Pack 2 for XP was an unique release for Microsoft. In contrast, SP3 will be noting more than a standard service pack. "Other companies would have called this a major release and charged money for it", stated Jim Allchin, the former Co-President, Platforms & Services Division, just a week ahead of his retirement from Microsoft, referring to XP SP2.

5. Do I have to wait for the RTM version of XP SP3 or can I get a taste of the service pack ahead of the final version?

Microsoft is offering a standalone version of Windows XP SP3 RC for download. However, users have to understand that despite the Release Candidate label and the proximity to RTM, XP SP3 RC is still a beta and should only be deployed into testing environments.

6. Does XP SP3 Release Candidate come with an expiration date?

Yes. All of the Redmond company's testing development milestones are time-bombed. This is also valid for XP SP3 RC, or any of its predecessor alpha builds. The expiration date is set for 180 days since the release. Users of the current beta releases of XP SP3 can open a Run dialog box, type "winver" and hit Enter. In the About Windows panel that will open, look for the expiration date associated with the evaluation copy of XP SP3.

7. How much will XP SP3 impact XP SP2?

Expect little and you won't be disappointed. The XP SP3 evolution will happen mainly under the hood, in terms of performance, security, and stability. SP3 will make available in a single package all the security updates, hotfizes and out-of-band updates, along with only a few minor enhancements. Users will not be able to see any modifications in terms of the graphical user interface and functionality. The few extra features added will only superficially affect user experience.

8. Are parts of XP SP3 already available as standalone downloads?

Yes. A few fragments of XP SP3 can already be accessed by XP SP2 users, but Microsoft will include them into the third and final service pack for XP. The features include the MMC 3.0 framework, MSXML6, Windows Installer 3.1, Background Intelligent Transfer Service 2.5, IPsec Simple Policy Update for Windows Server 2003 and Windows XP, Digital Identity Management Service, Peer Name Resolution Protocol (PNRP) 2.1 and Wi-Fi Protected Access 2 (WPA2).

9. Is Microsoft including parts of Windows Vista into XP SP3?

Yes. XP SP3, just as Vista, will include "Black Hole" Router detection, Network Access Protection (in view of the upcoming release of Windows Server 2008), Microsoft Kernel Mode Cryptographic Module and enhanced security for Administrator and Service policy entries. Microsoft will also revamp the information associated with the Security Options User Interface. And on top of it all, XP SP3 will feature the same product activation architecture as Windows Vista.

10. With the activation changes of XP SP3 will users need new product keys?

No. XP SP3 can be deployed on top of XP SP1 and XP SP2 with absolutely no issues. Users will not be required to enter, or re-enter their product key, or to re-activate the operating system. Furthermore, when performing a clean install of the XP SP3, users will have the possibility to deploy the operating system without entering a product key during installation. But they will have to deliver a product key by the end of the 30-day Initial Grace period and activate XP SP3.

Yet another (slightly different) FAQ can be found here. Enjoy :-)