Open it using the Notepad and replace anything by copying the following lines:
CODE
# Copyright (c) 1998 Microsoft Corp.
# This is a sample HOSTS file used by Microsoft TCP/IP stack for Windows98
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
# For example:
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host
127.0.0.1 localhost
...and save it to the same place.
Actually, all lines starting with # are comments, so you can type only
CODE
127.0.0.1 localhost
Maybe even this line is not necessary...