Interesting question. I am glad somebody asked it.
Windows XP's default configuration is far from optimized. This guide will help you improve your system performance with the Windows XP operating system. All of the programs listed in this guide can be found on our Support CDs. I avoid using or recommending "all-in-one" Windows XP Tweak programs since many blindly adjust settings that can cause future problems. This guide is designed to be performed top to bottom, in sequence since some steps are required to be performed before others.
Read More:
http://mywebpages.comcast.net/SupportCD/OptimizeXP.html
Is XP the fastest version of Windows ever? That's debatable, but this is not: like every operating system that came before it, it's not as fast as it could be without a whole bunch of fine-tuning.
Read More:
http://www.extremetech.com/print_article/0,3998,a=19543,00.asp
Do you work with Windows XP Professional or Windows XP Home Edition? Then, whether as a professional or an amateur you will certainly appreciate the Advanced XP Tweak software. Windows gets better with every year but there is always some room for development and improvement.
Read More:
http://www.tweakinternals.com/
Cheers,
McoreD