Defragmentation is the method in which contents on a hard disk can be physically organised and structured. It is a process that minimizes the amount of fragmentation in file systems. It does this by physically rearranging disk contents. Each file piece is stored tightly together and alongside each other. It also tries to create larger areas of free space that will in turn hinder the return of fragmentation by making sure all files are compact.
Its advantage is that results in nicely arranged files, which are not spread in pieces all over the hard disk. Besides defragmenting program files, the defragmenting tool can also reduce the time it takes to load programs and open files. After defragmenting your hard disk has faster access to the files, which results in a faster Windows. However, it may slow things down on older systems since its using resources when its running and it might not necessarily tidy all files in its first run as there can sometimes be frequent big gaps after defragmenting.
Standard Defragment Guide
To check for fragmented files and folders on a volume:
Defragment a Disk Volume:
If the Disk Defragmenter tool is not already running, click “Start”, point to “All Programs”, point to “Accessories”, point to “System Tools”, and then click “Disk Defragmenter”.
Click the volume that you want to defragment. Click “Defragment” to begin the operation. Review the progress of the operation in the Defragmentation Display window. Fragmented files on the disk appear in red, contiguous files are blue, and system files are green. The goal is to eliminate most of the red in the window.