Windows Xp SP3 may be the final service pack for Windows Xp , will include some bug fixes and have some of the features from Vista, has been estimated that service pack 3 will offer a ten percent performance enhancement. To download the SP3 then there is a hack which will allow to download the Xp SP3 RC1 directly from Microsoft.
Follow the following steps .
login in as administrator
double click to execute it
check for new updates in the windows update.
will find Service Pack 3 listed in the updates
Download and install