One of the best approaches to increasing your system's performance is to optimize the size of the PAGEFILE.SYS file because it acts as a virtual memory buffer on your system's main partition. It's a good idea to maximize the size of this file because it has a direct bearing on how many concurrent applications can be running at the same time and the depth of the memory they use. Keep in mind that the dedicated memory management of Windows NT, carried forward to Windows XP, is what makes a virtual memory partition highly recommended. Letting Windows XP actually define the size of this file is the best bet; you can, however, toggle it to your preferences. If your system is not running with PAGEFILE.SYS, make room for it and run it.
The second performance tip in this article was to customize the graphical interface for your system. Although selecting the option that optimizes performance creates the classic Windows look that has grayscale everywhere, you can still retain the colorful Windows XP desktop by deleting marginally useful graphical elements that drain system performance.
This series of articles will get down to the individual dialog boxes you need to work with to get the highest performance possible. Broader, more global statements on performance are useful, but it's been my experience that getting hands-on with your operating system always yields the best results.