The Windows Hosts file contains the mappings of IP addresses to host names. This 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 machine. Another feature of the HOSTS file is its ability to block other applications from connecting to the Internet, providing the entry exists.
When a web site or application calls up an advert it normally uses a standard URL like www.anADVERTsite.com which like any URL typed into a web browser must be translated into a machine recognised numerical identifier (IP address) which is a unique identifier of a location on the internet. Via. To block google adsense ads from appearing on your webpage, add the following lines to your windows host file.
# [Google Inc] 127.0.0.1 adwords.google.com 127.0.0.1 pagead.googlesyndication.com 127.0.0.1 pagead2.googlesyndication.com 127.0.0.1 adservices.google.com 127.0.0.1 imageads.googleadservices.com 127.0.0.1 imageads1.googleadservices.com 127.0.0.1 www.googleadservices.com 127.0.0.1 apps5.oingo.com
Location of Windows Hosts file:
Windows 95/98/Me c:\windows\hosts Windows NT/2000/XP Pro c:\winnt\system32\drivers\etc\hosts Windows XP Home c:\windows\system32\drivers\etc\hosts (you may need administrator access for Windows NT/2000/XP)
In most cases a large HOSTS file (over 135 kb) tends to slow down the machine. This only occurs in W2000 and XP. Windows 98 and ME are not affected. To resolve this issue (manually) open the "Services Editor"
* Start | Run (type) "services.msc" (no quotes) * Scroll down to "DNS Client", Right-click and select: Properties * Click the drop-down arrow for "Startup type" * Select: Manual, click Apply/Ok and restart.