Can't be done with native XP tools, you need something third-party to do it
at boot-time.
I use Raxco's PerfectDisk - they have a free trial that you can use. If I
remember correctly, O&O's defragger also has a go at the MFT and (again
IIRC) Diskkeeper's claims to do likewise amid some controversy - assertions
that it just pretends to defrag the MFT and fudges the results (I've never
liked that utility, anyway).
In view of Leonard's comment, it's perhaps worth mentioning that Microsoft
added the feature in Vista and called it an improvement. That said, there
may well be other, less arcane steps you could take to bring about more
noticeable performance increases.
For fuller information, do avail yourself of your favourite web-searching
engine or the history in these newsgroups - there's plenty to read up on
about it!