Block Any website on your computer

You dont need to download a website blocker for your PC.
just follow the procedure below :

1) Browse to C:\windows\system32\drivers\etc
2) Now, open hosts in Notepad.    
3) After 127.0.0.1, press enter and write this:127.0.0.2 www.xyz.com localhost
4) Now, save the file.
5) Reboot your PC.
6) All it has done Because website will not be opened again.