Usually every computer will come with a standard defragmenting tools, but using one is quite time consuming and not very user friendly. This will lead to "I'll do it later" habit which will worsen the fragmentation level of the drive.
Wait no more... after installing Auslogics Disk Defrag, the whole defragmentation process was a breeze, just select the drive :
Click next and watch the whole process or leave it on it's own.
After that, just click finish and voila!, it's done.
And best of all, it's free.
For the latest version, please visit their website at http://www.auslogics.com/
Download page at http://www.auslogics.com/en/software/disk-defrag/download