Blocking Websites Using the Windows Hosts FileThere are a lot of tools available for blocking ads, removing spyware, scanning for viruses. Most of this unwanted content comes from known ad servers and known malicious websites.
The Windows
HOSTS file allows you to block some of this content very easily and for free. However, this is not a complete internet security solution. It is still recommended that you run anti-virus software on your computer and be careful of the websites you visit.
Defining the HOSTS fileThe
HOSTS file is located in the following locations for the respective versions of Windows:
Windows 7, Windows Vista, Windows XP, Windows Server 2003:C:\WINDOWS\system32\drivers\etcWindows 2000:C:\WINNT\system32\drivers\etc\Windows 98/ME:C:\WINDOWSThe
HOSTS file does not have an extension, but it is a plain text file. This file allows you to manually associate IP addresses with domain names (i.e., google.com) so the
Domain Name Server (DNS) can quickly resolve an address.
To use the
HOSTS file to block a website, assign the
IP address of 127.0.0.1 to the domain name of known ad servers and malicious websites.
127.0.0.1 is the IP address of your local computer, if you chose to run a server on it.
As an example, let’s say some ad server hosts a banner ad at the
URL: http://www.adsite.com/ads/12345.jpg. If you associate this domain name with the IP address of your local computer,
127.0.0.1, when that website tries to load that image, it will not be found because the image file does not exist on your computer. Therefore, the ad will not display on that webpage.
Editing the HOSTS fileSince the
HOSTS file is a text file, open the file in
Notepad, or other text editor, to edit it. This first line of the HOSTS file should list the local IP address:
127.0.0.1 localhostThat tells the rest of the file that
127.0.0.1 is your local machine, as mentioned above.
You could also use 0.0.0.0 instead of 127.0.0.1 — either will work. However, whichever IP address you use for localhost, also use for the sites you want to block.
After the
localhost entry, enter known ad servers and malicious websites and assign your local IP address to each domain name. Put the IP address at the beginning of the line, followed by a tab, followed by the domain name for the ad server or malicious website. Here’s an example of the
HOSTS file:
NOTE: Some spyware programs automatically add ad servers and malicious websites to your HOSTS file for you.For Windows XP/2000 users onlyIn
Windows XP and
Windows 2000, if your
HOSTS file gets to large (over 135 kb), the
DNS Client (a system service) will cause problems on your machine possibly causing it to lock up. This service is unnecessary and can be stopped and disabled.
Therefore, before you save a big list of ad servers and malicious websites in the
HOSTS file, select
Control Panel | Administrative Tools | Services from the
Start menu.
Scroll down to the
DNS Client service, right-click on it, and select
Properties from the pop-up menu.
The
DNS Client Properties dialog box displays. Select
Manual from the
Startup type drop-down list. Click
Stop below
Service status to stop the service. Click
Apply and then click
OK.
For more information about the
HOSTS file, see
http://accs-net.com/hosts/what_is_hosts.html. You can find maintained
HOSTS files online or start to build your own. See
http://www.mvps.org/winhelp2002/hosts.htm to download a good, free, pre-populated HOSTS file.
There is a
.zip file for download containing the
HOSTS file, a batch file for easy installation, and a readme file with instructions for installation in the different versions of Windows. Beware that there are special instructions for
Windows Vista and
Windows 7.Also have a video on how to use host file
