How to block certain websites on your computer

Some times in your home you find that other people who are also using the same computer are using some unwanted websites. And you need to block all those websites which you don't want other people to access. There are lot of tips and tricks using which you can stop them to visit those websites.
1.(a)Go to start type run type notepad c:\WINDOWS\system32\drivers\etc\hosts.  
(b) You will get a notepad with some cryptic symbols and lot of thing don't be panic just go down and write down these lines
127.0.0.1 orkut.com
127.0.0.1 facebook.com
127.0.0.1 myspace.com
save the notepad restart the computer and now all these listed websites are blocked.
2.(b) Go to control pannel then go to internet option click it and you will get a dialog box like this

 Go to restricted sites and you will again get a dialog box now add websites you don't want to visit. Apply it and now restart the computer, now you can't visit those added sites
These are websites go to these websites and going through the advise or instruction you can restrict others to view these sites
http://www.opendns.com/start/ 
http://www.monitoring-softwares.com/pare… 
http://www.mywot.com/ 
but i personally recommend you WOT this is the site which will give you restriction not to use any unwanted websites. A websites having lot of malware  and virus are allready restricted.

ChildWebGuardian http://www.childwebguardian.com/
 Safe Eyes http://www.safeeyes.com/
These are also some websites they also provide you restriction to block unwanted websites but you need to pay money for it