Help opening certain websites

I recently purchased Panda Anti-virus software, but I am having trouble accessing their site to register it. I have contacted Panda and also my ISP, and neither is any help. Every other website I go to works fine. I am running Windows XP with SP2, 512 RAM, P 4 2.0 GHZ. This is the error page
The page cannot be displayed
The page you are looking for is currently unavailable. The Web site might be experiencing technical difficulties, or you may need to adjust your browser settings.

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Please try the following:

Click the Refresh button, or try again later.

If you typed the page address in the Address bar, make sure that it is spelled correctly.

To check your connection settings, click the Tools menu, and then click Internet Options. On the Connections tab, click Settings. The settings should match those provided by your local area network (LAN) administrator or Internet service provider (ISP).
See if your Internet connection settings are being detected. You can set Microsoft Windows to examine your network and automatically discover network connection settings (if your network administrator has enabled this setting).
Click the Tools menu, and then click Internet Options.
On the Connections tab, click LAN Settings.
Select Automatically detect settings, and then click OK.
Some sites require 128-bit connection security. Click the Help menu and then click About Internet Explorer to determine what strength security you have installed.
If you are trying to reach a secure site, make sure your Security settings can support it. Click the Tools menu, and then click Internet Options. On the Advanced tab, scroll to the Security section and check settings for SSL 2.0, SSL 3.0, TLS 1.0, PCT 1.0.
Click the Back button to try another link.



Cannot find server or DNS Error
Internet Explorer

I know that the site is up because I have gotten on on other computers. Thank you for your help

 

go to start.. run type the following in and hit enter

C:\windows\system32\drivers\etc\hosts

The file that comes up should look like this


# Copyright (c) 1993-1999 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

127.0.0.1 localhost


if a program list box pops up asking you what program to open the file in, choose notepad from the list and hit ok.

If there are any entries below the local host line, then remove them all, save the file and try again.