Everyone who owns a computer for a some time, knows (or will), that eventually needs to defragment the hard drive. When we use the computer more and more, files become disordered  and our system slows down as a result. Why?

Fragmentation occurs when the operating system cannot or will not allocate enough contiguous space to store a complete file as a unit, but instead puts parts of it in gaps between other files (usually those gaps exist because they formerly held a file that the operating system has subsequently deleted or because the operating system allocated excess space for the file in the first place). Larger files and greater numbers of files also contribute to fragmentation and consequent performance loss. Defragmentation attempts to alleviate these problems.

Wikipedia

This happens all the time after installing and uninstalling programs (they can leave files behind), system freezing during writing to the hard drive, copying and deleting files (think of your music files, movies), etc.

As you ad more files to your computer over time, Windows has to find places on your hard drive to store them. Often this means splitting the files up into pieces and storing them in chunks throughout the hard drive. This is perfectly normal, but it slows things down because at the time you access any of those fragmented files, to watch a movie for instance, Windows then needs to reassemble the fragments. Using a disk defragmenter should reorganize this data on your drive so that files are store contiguously, making it faster for Windows to open the files later. This is especially important for disk-write intensive tasks like video editing.

Over time, fragmentation can become a big problem if left unchecked. As pieces of files become spread out, the hard disk’s read/write heads have to do more work to locate and transfer files to memory. The more the read/write heads move, the longer it takes to access files. Consequently, hard disk performance suffers.

Vista’s defragmenter

Every Windows has built in defragmenter. But Vista’s is quite different. There is no progress bar or legend.

1. The lack of a graphical analysis display in Vista is a problem. It really
   is much easier to glance at a picture and understand what is going on.
2. The Vista command line defrag verbose report does not include individual
   file information (as the XP analysis report does). This further hampers your
   ability to understand what is going on.
3. The XP defrag cleaned up a mess left by the Vista defrag - shouldn’t this
   be the other way around?
4. Why is the free space not defragmented? Given the current scheme when you
   load up one massive video file it is automatically broken up into thousands
   of small pieces.

(it looks like I’ve never run it )

By default defragmenter is scheduled to run once every week. You can force the defragmentation to start immediately by clicking on the “Defragment now” button of course. This is all what Vista’s tool offers.
However, others do not recommend using third party disk defragmenter. The reason is the disk defragmenter included with Vista takes many things into consideration when defragmenting hard drive like file shadowing, backups, etc.

Command Line, not only for power users

The command line version of disk defragmenter uses the exact engine as the GUI (regular) version but you have finer control of the defragmenter.
It does not defragment files in the Recycle Bin, or files which are in use. It does not degragment Bootsect dos, Safeboot fs, Safeboot csv, Safeboot rsv, Hiberfil sys, Memory dmp, or the Windows page file as well. Using the -b parameter will optimize these boot files.
The command line version becomes much more powerful and flexible when you add switches to the defrag command. Below are switches that can be used when running the defrag command:

• -c defragments all drives
• -a analyses the drives and gives you a report. (does not defragment the drives)
• -r only defragments files that are smaller than 64MB in size.
  This is the default setting of the defragmenter. Microsoft research shows that there’s no performance gain when defragmenting files larger than 64MB in size.
• -w defragments all files regardless of size.
• -f forces defragmenter to defragment drives with less than 15% of hard drive space left
• -v displays a complete (verbose) report

If you find that you are unable to defragment or cannot run the defragment utility in Vista or that a drive or volume has been marked by Vista as having errors, run chdsk by typing at the command line chkdsk c: /f (where “c” is a drive letter)

• To view a fragmentation analysis of your D: drive, use:
  defrag d: -a –v
• To defragment a particular drive, e.g. C:
  defrag c: -v -r
  (-r - treat files that are fragmented with 64 MB fragments or larger)
• Defragment everything, even if the file fragments are larger than 64MB
  defrag c: -v -w
  (-w - do a full defragmentation)

The only indication you will get is a blinking cursor. This is the only message that the process is going. To stop the defragmentation process, use Ctrl+C in the command window.

An example output, shown below, runs analysis on the D: drive with verbose mode:

So, defragment or not?

Now you know. Stay tunned for a review of free third party tools.