You can make Windows XP boot faster by 5 - 15 seconds (on some machines).
To do so do the following:
1. Start Registry Editor (Regedit.exe).
2. Locate the following key in the registry:
1. Make sure you backup the keys by exporting them to a .reg file.
2. On the EnablePrefetcher value, change the setting from 3 to 5 (decimal).
3. Close the registry editor.
4. Restart your computer.
Note: Whatever you do DO NOT install a tool called BOOTVIS from Microsoft, unless you're absolutely sure of what you're doing and have good knowledge of the tool and it's use.