once you have found it, right click it and select "properties". uncheck the "read-only" box and click ok. then double-click the hosts file and select notepad from the list of programs. once you have that you'll see an entry like 127.0.0.1 localhost
to block a certain web page, enter something like 127.0.0.1 www.webpage.com (you can enter any url you want).
your hosts file will now look like this:
127.0.0.1 localhost
127.0.0.1 www.webpage.com
Attention: NOTHING on this site may be reproduced in any fashion whatsoever without explicit consent (in writing) of the owner of said material, unless otherwise stated on the page where the content originated. Search engines are free to index and cache our content. Users who post their account names or personal information in their questions have no expectation of privacy beyond that point for anything they disclose. Questions are otherwise considered anonymous to the general public.