Solution 1: Modify host file (Only for Windows)

This is the easiest way to block any website to access from your computer. It doesn't require any software installation or configuration changes.

Below is the step by step process to block a site from your PC:

1. If you are using Windows XP go to following location and open "hosts" file in notepad.
             C:\WINDOWS\system32\drivers\etc
   
   Note: For all other Windows operating System, search for "hosts" file in your PC and open it in any text editor like notepad.
   
   
2. Add an entry like below at the bottom of this file.
             127.0.0.1 *.xyz.com
   
   You can make as many entries as you want to this file.
   
   
3. Save and close the file. Close all browsers open them again to activate these settings.