Why don't you slipstream SP3 into your Windows XP disc? In this way, you will automatically install SP3 when you install Windows XP, saving you the hassle of upgrading, which costs time and prone to failure
The software that you need is called nLite. Run it and it will guide you through the whole process. You will need a Windows XP installation disc (any "recovery disc" bundled with your PC won't work), the SP3 installation package, nLite itself, and a blank disc to burn the new SP3 slipstreamed installation program in
nLite:
http://www.nliteos.com/
Windows XP SP3 (you must use this version - others won't work):
http://www.microsoft.com/downloads/d...8-1e1555d4f3d4
Good luck
