is your internet connection ok?
how are you connecting Wireless or LAN?
open command prompt and type the following command
ping www.google.co.uk
and see if you get a response
some occasions viruses and malware can block access check you have not got a proxy setup.
open internet options
click connections
click Lan settings
make sure Proxy server is unchecked if you do not use one
the other thing to check is your hosts file
open command prompt and type the following command
type C:\windows\system32\drivers\etc\hosts
and make sure it looks the same
# Copyright (c) 1993-2009 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# 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
# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost
Kind Regards