WinXP uses Diskeeper Lite
From Diskeeper.com
Diskeeper Lite is back in a new improved version. Diskeeper Lite is a fully operational, free manual-only version of Diskeeper. Diskeeper Lite can rapidly analyze fragmentation levels and detect them automatically. This version includes the same advanced defragmentation technology used in Diskeeper 7.0 and it runs on all Windows operating systems from 98 through XP.
All "Set It and Forget It"® scheduling, system management functions and network controls are shown and explained, but rendered inoperative.
Diskeeper Lite is an ideal download for everyone serious about automating defragmentation but would like to know more about Diskeeper first. Lite will help everyone select the right full-featured Diskeeper version(s) for their homes and/or business sites.
Yes, it's based on Diskeeper Lite but it does do an automatic boot optimization if you don't go in and disable that. It only does it if the machine is idle for a period of time.
Quoted from
http://www.extremetech.com/article2/0,2845,1786009,00.aspWindows XP includes a boot defragmenter but it is a little tricky to get it to run. By default, it is run only in the background and cannot be started directly by a user. After your computer has been idle for some time between 5 and 30 minutes, the system will read the prefetcher's boot data and start the defrag. The system defrag is run in the background and is invisible to the user. Eventually, if you leave your computer on long enough, it will be defragment the boot files
Microsoft has a very talented team working for them and they even took into consideration that often your system boot changes. For example, you might install an updated device driver or add new hardware. To solve this problem, the system will re-defragment the boot files every three days.
Tip:
Windows keeps track of the last time it optimized the boot file so that it can calculate how often it should run the boot defrag. If you are interesting in finding when the last time was that the boot defrag was run, open up regedit and navigate to: "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Prefetcher" and then look for the key named "LastDiskLayoutTimeString".
Mine was last done at 4:40 PM yesterday.