Gary Stern said..
There are lot of utilities & software available on the net to block specific site on your PC some of those are
Website Block
This utility allows you to block unwanted websites from display in Internet Explorer. Features are
Block websites of your choice.
Block porn, block adult content based on keywords in URL.
Use password protected mode so that other users can not change settings.
Allows saving and opening blocked websites profiles.
Includes password protected uninstall.
Easily block MySpace, block Facebook and other social networking sites.
Reduce your internet traffic by blocking ads and banners.
Selectively block websites by keywords appearing in URL. Block porn sites, block adult websites by typing unwanted keywords that may be found in the full URL.
You can download it from
http://www.ashkon.com/download/webblock.exe
BlockSite is an FireFox extension, which automatically blocks websites of your choice. You can add and/or remove websites, you don't want to visit ever again, via the BlockSite Preferences
You can download it from
https://addons.mozilla.org/en-US/firefox/addon/3145