I ran Defraggler and found it left a fragmented restore point. Having used the Microsoft Disk Defragmenter in Windows XP a lot I was a little surprised. I decided to create a System Restore point and then ran Disk CleanUp to remove all but the latest restore point. Ran Defraggler and there were no files listed as fragmented.
I am not sure that the fragmented files list is 100% correct. It does not list the MFT, which is normally in 2 or 3 fragments. Notwithstanding Defraggler impresses. One feature in Vista I find unhelpful is that the Disk Defragmenter provides little information and the user interface is not user friendly. Defraggler satisfies most of my requirements in this respect.