Hack Attack: Get Windows XP SP3 Through Windows Updateby Nikola Strahija on November 29th, 2007 Well here is how you can download SP3 straight from Microsoft. Follow the instructions carefully and you'll be running Windows XP SP3 in no time.
[list][*]Download this file ( [url=http://www.xatrix.org/download/windowsxpsp3hack.cmd]WindowsXPSP3Hack.cmd[/url] -- save target as ). Once you have downloaded the file, login as administrator and run the file by double clicking it. Wait for the Confirmation Message on screen.
[*]The Above file adds a few entries to the Windows Registry that makes Microsoft think that you are a part of the Private beta program.
[*]Check for new updates on Windows Update. You should now see Windows XP SP3 listed in the available updates.
[*]Download and install it. Reboot whenever necessary.[/list]
Please note this hack is the exact way Microsoft expects its beta testers to try Windows XP SP3 out, so you don’t have to worry too much about Microsoft catching hold of you.
Apparently, this has been tried on a plain Windows XP installation and worked like a charm. If you can’t wait for Microsoft to release SP3 officially then this should ease your pain.