The hosts file is a computer file used by an operating system to map hostnames to IP addresses.
On many operating systems, the host file content is used preferentially over other methods,
such as the Domain Name System (DNS). Unlike DNS, the hosts file is under the control of the local computer’s administrator
Locate the file “Hosts” on your computer:
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
/etc/hosts or /etc/host.conf or /etc/nsswitch.conf
/private/etc/hosts or /etc/hosts
In that file you can edit entry like this
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost.localdomain localhost localhost yourlocaldomain.com , example.com
::1 localhost6.localdomain6 localhost6