The hosts file is a computer file used to store information on where to find a node on a computer network. This file maps hostnames to IP addresses (like 10.0.0.1 points to www.google.com). The hosts file is used as a supplement to (or a replacement of) the Domain Name System (DNS) on networks of varying sizes. Unlike DNS, the hosts file is under the control of the local computer’s administrator (as in you). The hosts file has no extension and can be edited using most text editors.
The hosts file is loaded into memory (cache) at startup, then Windows checks the Hosts file before it queries any DNS servers, which enables it to override addresses in the DNS. This prevents access to the listed sites by redirecting any connection attempts back to the local (your) machine (ip address 127.0.0.1). Another feature of the HOSTS file is its ability to block other applications from connecting to the Internet, providing the entry exists.
So you can use a HOSTS file to block ads, banners, 3rd party Cookies, 3rd party page counters, web bugs, and even most hijackers, so here are some instructions to do so and some sites with already made hosts files (you just overwrite your own hosts file):
The host files location is:
Windows XP at c:\Windows\System32\Drivers\etc
Windows Vista at c:\Windows\System32\Drivers\etc
Windows 2000 at c:\Winnt\System32\Drivers\etc
There you will find a file named hosts (no extension), like we said above you can edit it with any text editor, and function is simple, you map ip addresses to hostnames, so the files will be mostly like this…
127.0.0.1 localhost
127.0.0.1 www.bad-spyware-site.com
127.0.0.1 www.site-with-virus.com
127.0.0.1 www.publicity-ads-site.com
if you want to add any domain, just add a new line right 127.0.0.1 for the localhost (this way when that domain comes up in the browser the browser will search for it on your computer and not online, because the hosts file told him that), so for example:
127.0.0.1 localhost
127.0.0.1 www.bad-spyware-site.com
127.0.0.1 www.site-with-virus.com
127.0.0.1 www.publicity-ads-site.com
127.0.0.1 google.com
so now if i put google.com on the address bar of the browser it will give me a blank page and google.com wont work anymore, if you want to delete a entry, just delete the line or put a # in front
127.0.0.1 localhost
127.0.0.1 www.bad-spyware-site.com
127.0.0.1 www.site-with-virus.com
127.0.0.1 www.publicity-ads-site.com
#127.0.0.1 google.com (google.com will work now)
so the idea is to use the hosts file to block unwanted or bad sites ^-^ clean and easy hehehe
Here are some sites that provide awesome host files ^_^ .oO (choose one of them)
Hostman : Its an automated hosts file updating software
Host File : Pretty cool and clean hosts file
Someone Who Cares : A compreensive hosts file
MVPS : A hosts towards blocking unwanted stuff