BleepingComputer.com: Windows defrag results

Using the standard, built-in Windows XP, defragmentation. Not in safe mode. Just in Windows mode. After about six months of not defragmenting.
After doing defragmentation, the official report states that free space is not fragmented and only 2 files are fragmented. One of them is likely page file.
Yet the visual display shows all these little blue lines (blue=not fragmented) scattered all over the place, all over the white areas. White areas are free space. Avg file size is 1/2 meg according to the post-fragmentation report.
Is this ok?
I would have thought that all the white space would be roughly contiguous, not split up by files here and there. And that all the blue lines would get compacted into roughly one bigger blue area.

Any explanations, other that use some downloaded product, are most welcome.

This post has been edited by tos226: 09 April 2011 - 07:21 PM

The built-in Windows XP defragmentation utility generally only defragments individual files and does not attempt to compact them together. By and large this is fine.

Third party defrag utilities often do attempt to compact files towards the beginning of the drive though the value of doing this is arguable. Compacting all the files end-to-end means that if a file later gets bigger then it must be fragmented since there's no extra room around the file to expand in to. Conversely, if a file gets smaller then you are left with a very small gap between files which will be skipped by Windows when saving a new file since there isn't enough room to store the file without fragmenting it.

This post has been edited by Andrew: 09 April 2011 - 07:59 PM

Andrew, what would we do without you
What you wrote totally makes sense. Considering how infrequently I defrag, it took me by surprise, but I love your balanced opinion - THANK YOU!

You're quite welcome.