How to block any websites in your system : A very simple way

1. open the notepad as administrator.
2. select file->open
3. type this "c:\windows\system32\drivers\etc\hosts" and click open
4. type "127.0.0.1 www.google.com" and save it.
5. then open the browser and in the url type "www.google.com"
6. you can see the page like this.

If u want to unblock, remove that line.