Whenever you store data on a computer, after a while the data can become fragmented, thus making it take longer to load and potentially become corrupt. To prevent this from happening, you can Defragment your hard drive using a built in tool from Microsoft. However, some times the built in tool is slow or does not do the job correctly. This is where Defraggler can help.
There are many tools all over the net which can defragment a computer, however I prefer using Defraggler for its ease of use and reliability. When you open Defraggler, it immediately gives you a nice clean interface, displaying your drives and a visualization of how fragmented they are.
As you can see, defraggler also offers a file list view, which can show you each individual peice of data which is fragmented. For the more advanced user, you are also able to search for files based on their size or file name.
All in all, Defraggler is a great program for defragmenting your hard drive, and I would definately reccomend it over the default program from for windows.