This is simply a reminder post to myself because I always have trouble finding this file. To update host file in windows 7 navigate to:
C:\Windows\System32\drivers\etc
From there just double click the host file and input a url in the following format
IP address example.com
This is really useful for testing website code once you have moved it from your local server onto your production server without actually needed to update the DNS of the domain and potentially sending live visitors to a broken site.