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). This fragmentation causes your hard drive to run slower and fragmentation will build after time.

To Defragment your hard drive, open up "My Computer", Right Click on C:, Click properties, Click the "Tools" Tab, Click "Defragment Now", Click Defragment, click ok .

This is a pretty easy and painless operation. If you computer doesn't have enough free hard drive space, windows will not allow you to defrag. This is the only snag I have seen with the defrag utility. However, if you don't have enough hard disk space to run the defragmentation utility, your computer may be slower due to this and it is a good idea to free up some disk space. I would recommend running this tool every month or two. Also, I often get the message that windows does not need to defrag. I usually go ahead and run the defrag utility anyways. I would recommend doing the same to keep your drive at its best.