The best collection of free utils for Windows can always be found here:
http://www.filehippo.com/
A couple defrag utils are among them.
-S
PS. This is the list to choose from for File Hippo:
O&O Defrag 2000 Freeware
O&O Software - 2.08MB (Freeware)O&O Defrag 2000 is a freeware Windows defragmentation tool. It is completely integrated into the Microsoft Management Console as a snap-in and can be ...
Download
JkDefrag 3.36
J C Kessels - 467KB (Open Source)JkDefrag is a disk defragmenter and optimizer for Windows 2000/2003/XP/Vista/2008/X64. Completely automatic and very easy to use, fast, low overhead, ...
Download
Defraggler 1.10.143
Piriform - 809KB (Freeware)From Piriform, the company that brought you CCleaner and Recuva... they now bring you a file defragmentation tool... Defraggler!
Download