Block sites without any softwares.

For eg you want to block www.123.com !
* Open the folder C:\WINDOWS\system32\drivers\etc
* There you will find a file named HOSTS
* Click on the file and press SHIFT and now right click on it .
* From the right click menu select Open with .
* Now, select Notepad to open the file from the list !
* Now, in the file under the line 127.0.0.1 localhost add another line as 127.0.0.2 www.123.com.
* Now, File>>Save !
Now, open your web browser and try opening www.abc.com , it will not load !