XP's memory manager module includes a prefetcher component that runs at system startup and fetches commonly used programs to speed their execution. This component slightly increases the amount of time to start the OS. Although Microsoft doesn't recommend disabling the prefetcher, you can disable this component (e.g., for troubleshooting purposes or to speed boot time) by performing the following steps: Start a registry editor (e.g., regedit.exe). Navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters subkey. Double-click EnablePrefetcher, set its value to 0, and click OK. Close the registry editor. When you reboot the system, the prefetcher won't execute.