Microsoft has recently confirmed that it is creating a third Service Pack for Windows XP.
A “service pack” (or SP) is a collection of patches, fixes and general improvements that Microsoft believes will make the operating system work better.
Early testing on SP3 indicates that not only is does it show a 10% improvement in performance (read speed) over Windows XP Service Pack 2, but it makes Windows XP work almost twice as fast as Windows Vista with Service Pack 1 installed. You can read details of the testing here.