block/unblock websites without any software

Many times in schools, colleges
& offices surfing some sites are
banned... To overcome this you can
unblock these or block some
other websites and play
pranks ! Do The Following :
For ex
ample you want to block facebook :

* Open the folder C:\WINDOWS
\system32\drivers\etc
* There you will find a file
named HOSTS
* Click on the file and right
click.
* 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 facebook .
* File > Save. Now, open your web browser
and try opening facebook , it will not load... To unblock sites just do the
opposite ! ideal toh para sa mga
nagwowork na hindi makapag fb sa office.

tnx