|There's a few ways depending on what browser you use & how professional you need websites blocking. For Firefox there are addons that can block, but may be still accessible through other browsers. There's software you can buy to block websites from multiple computers etc.|
The easiest way would be to use Windows Live Essentials. There's a Family Safety program that can block websites and monitor users.
When installing just select family safety.
Another way, without downloading is a little more complicated but doesn't require a download. Instructions below anyway. Any questions just reply.
Editing Hosts file
1. Open Notepad as Administrator. (Right click, Run as Administrator)
2. File > Open > Navigate to C:\ > WINDOWS > system32> drivers > etc
3. Bottom right it says "Text Documents(*.txt)". Change that to All Files.
4. You should see a Hosts file appear. Click that and open it.
5. Now you'll have some text in the file, Just leave all that and scroll to the bottom & make a few lines.
If you want to block facebook, you need to enter the bold text.
Then save the file. So the bottom half should look like mine but the top bit may be different, that doesn't matter;
# 220.127.116.11 rhino.acme.com # source server
# 18.104.22.168 x.acme.com # x client host
# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost
Then you need to go to Start > type "cmd" press enter.
After all that, the websites should be blocked in all browsers. But remember, you need to cover all URLs of the website, If you put only facebook.com. It will still be accessible by www.facebook.com as it reads it differently.
And Proxy websites etc will easily work as a bypass. But It's ok for non-literate PC users.