Defragmenting your hard drive helps maintain and speed up your computer.
Whilst Windows 10 is usually set to run this automatically, running a defragment after a disc clean up is a great idea.
Solid State Hard Drives
Conventional wisdom is that SSDs don't need to be defragmented, in fact at this time it is recommended not to do so.
To Run a disk Defragment:
Click Search (1)
Type Defragment (2)
Click Open (3)
Your Systen disk is C Drive:
Highligh C: by clicking on it (4)
Click Optimise (5)
The most important drive to optimise is your C: drive however defragmenting your other drives doesn't hurt either