There are many software in the market to block sites .But in every method You have to type the websites which you want to block in your computer.
Today i have a simple tut to do that but i am not using any high weighted software which slows down my computer.We just need a notepad which is pre-built installed in every version of microsoft windows .
1: Go to start and click on run or just press windows button + R
2:In the empty bar just put the following code
3:After this press ok you will see this type of window
4:Type here the sites you want to block with ip as shown in the below picture
5:Now click on save and You have blocked the sites
NOTE:You have to write one site twice as i have written to work it proerly.