Vista and hosts file

With Vista, you can't modify hosts file directly with a normal user. You have to become an administrator to edit the file.  Here's how:

Run text editor such as notepad as Administrator, by right-mouse clicking on the application, and select "Run as administrator".

You'll get system notification, click "Continue"

Open file, C:\Windows\System32\Drivers\etc

hosts file doesn't have any file extension. Select "All Files"

Open "hosts" file.