Every version of Windows have disk defragmenter utility.But with this you can not defrag an individual file or folder .It defragment entire hard drive at once and ignore files below 64KB. Contig is a single-file defragmenter that attempts to make files contiguous on disk. Its perfect for quickly optimizing files that are continuously becoming fragmented, or that you want to ensure are in as few fragments as possible.
For instance, to defragment all DLLs under Windows you could enter you could enter "contig -s D:\WINDOWS\*.dll".
To make an existing file contiguous use Contig as follows:
Usage: contig [-v] [-a] [-q] [-s] [filename]
-v Use the -v switch to have Contig print out information about the file defrag operations that are performed.
-a If you want to simply see how fragmented a file or files have become, use the -a switch to have Contig analyze fragmentation.
-q The -q switch, which over-rides the -v switch, makes Contig run in "quiet" mode, where the only thing it prints during a defrag run is summary information.
-s Use the -s switch to perform a recursive processing of subdirectories when you specify a filename with wildcards.
To make a new file that is defragmented upon creation, use Contig like this:Usage: contig [-v] [-n filename length]
You can run Contig from the command prompt,but with the help of another tool it is more easy and have more visual interface.Power Defragmenter is a graphic user interface designed to use Contig program.With this you can visually select files, folders and drive you wish to defragment.