What to do to block or unblock websites.....

Many times in schools, colleges & offices surfing some sites like orkut, etc are banned !
 

To overcome this you can unblock these or block some other websites and play pranks !
Do The Following :

For eg you want to block www.xyz.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 lines 127.0.0.2 www.blablablabla.com.
* Now, File>>Save !
Now, open your web browser and try opening www.blablablabla.com , it will not load !
To unblock sites just do the opposite !