There are some unwanted files and registry errors which uses system space and slows down your system. These files can be deleted manually but it takes some time.
There is a software by Ccleaner which deletes all unwanted files and folders in recycle bin, deletes cookies of internet browsers and registry errors etc. This software can be downloaded from here
Download the installation file and install it on your system. Once it is installed on your computer, Open it by double clicking on the shortcut on your desktop
Once it is open, click on the button by name “Analyse”
Once you click on the analyze button it shows how much MB of files will be removed from your computer.
Click on the button “Run cleaner”
It deletes all the unwanted files and temporary files stored on your pc and your system will run fast.