If you mean fragment as in break up the files so that you can review defragmenting programs or something, then nothing that will perform the same amount of fragmenting every time BUT
Set a dynamic pagefile reduce system RAM and set a huge recyvle bin, and temporary internet folders. Goto a lot of video sites (like you tube, copy and delte some really large files around your hdd, and do this for a couple of hours.
Alternatively, a fresh install of XP pro ends up around 30% fragmented IIRC. (unless you have a pretweaked install disk)