Mike Brannigan of Microsoft has advised Windows XP users to stay clear of the Fake Windows XP SP3 package that is easily available for download acrosss the internet. Hotfix.net, who created the "Preview" XP SP3 package, claim that the Windows XP Service Pack 3 Preview package is 100+ hotfix pack of many of the Windows XP SP3 fixes up for download.
Microsoft has warned that the package is NOT suitable for testing as it is NOT SP3. Anyone who installs this thinking they are getting SP3 (even as a preview) is being grossly mislead and is posing a significant potentially non recoverable risk to their PC and data.
Here's the full warning posted by Mike on Windows XP newsgroup.
It will not update your Windows XP system to SP3. It also contains a number of private " hotfixes that are usually only issued to users with a specific identifiable problem. The hotfixes are not as rigorously tested at public released ones this is why we ask you to call PSS to get them so we can track you and provide further assistance such as new versions of the fixes etc as they become available. Just installing all the "privates" on your PC may make you machine LESS stable and will also put you out of support from Microsoft or an OEM as you are installing incorrectly issued private hotfixes.
Frankly this "package" should be avoid and you should continue to use Windows Update and the download site to get the most up-to-date and correctly issued Microsoft fixes and patches.