Simple step to block facebook with easy way.
Please make a Backup of your hosts file in case of anything happened.
1.) Click Start, click Run or press Windows + R
2.) Please copy the below string based on your Operating System.
Windows 98/ME
C:WINDOWShosts
Windows 2000
C:WINNTsystem32driversetchosts
Windows XP, Vista and Windows 7
C:WINDOWSsystem32driversetchosts
3.) Click Enter and then open the hosts file and using notepad to open it.
4.) Please copy and paste the following into the notepad file.
# Block Facebook
127.0.0.1 www.facebook.com
127.0.0.1 facebook.com
127.0.0.1 static.ak.fbcdn.net
127.0.0.1 www.static.ak.fbcdn.net
127.0.0.1 login.facebook.com
127.0.0.1 www.login.facebook.com
127.0.0.1 fbcdn.net
127.0.0.1 www.fbcdn.net
127.0.0.1 fbcdn.com
127.0.0.1 www.fbcdn.com
127.0.0.1 static.ak.connect.facebook.com
127.0.0.1 www.static.ak.connect.facebook.com
127.0.0.1 www.facebook.com
127.0.0.1 facebook.com
127.0.0.1 static.ak.fbcdn.net
127.0.0.1 www.static.ak.fbcdn.net
127.0.0.1 login.facebook.com
127.0.0.1 www.login.facebook.com
127.0.0.1 fbcdn.net
127.0.0.1 www.fbcdn.net
127.0.0.1 fbcdn.com
127.0.0.1 www.fbcdn.com
127.0.0.1 static.ak.connect.facebook.com
127.0.0.1 www.static.ak.connect.facebook.com
5.) Save your Hosts file and your are done.