Using the hosts file, ip addresses can be mapped to hostnames. This is useful to access systems that do not have a DNS entry and for test and development purposes.
The hosts file exists in the SYSTEM32\DRIVERS\ETC directory under the Windows root directory (i.e., \WINDOWS or \WINNT). Edit this file and add a line like the following:
192.168.1.15 testserver test.domain.com
This would map two names to the ip address 192.168.1.15, testserver and test.domain.com
For most installations of Windows including XP, Vista, and Windows 7, the location of the hosts file is the following: