If you can’t connect to certain web sites using your favorite web browser, there could be several reasons why. Here are a few things you can try to clear up the problem.
Symptom: In Firefox you get “Firefox can’t establish a connection to the server at website” or in Internet Explorer you get “Page cannot be displayed” error.
This article assumes you have troubleshot the basics such as the URL is typed correctly, cache files have been cleared and you have a working internet connection.
1. Flush the DNS Cache.
In some cases, flushing the DNS cache may help. You can flush the DNS by holding down the Windows key on your keyboard and pressing R to bring up the Run box. Then type ipconfig /flushdns and press Enter.
2. Spyware may have modified your HOSTS file.
To check it, go to Start > Run:
Windows 7, Vista, XP and Windows 2000 users type:
Windows 98 and Windows ME users type:
Open the file called HOSTS using NOTEPAD or WORDPAD.
Each entry will look something like the following:
Entries like this will block access to the sites listed. Look for entries like this referring to any web site you may not be able to access and delete them.
Note: For most users this file is blank. Unless you have any type of special configuration for systems on your network, the HOSTS file isn’t normally used. It is most likely safe to remove all entries from this file.
You can find more information about HOSTS files here.
3. Firewall software is blocking access.
Disable your firewall. The following links may help.
If that doesn’t work, uninstall the firewall software.
Firewall software can block your connections even if it is disabled.
4. Problems with sites that use SSL
If the problem is only with sites that require a secure or SSL connection, you might want to troubleshoot the browsers ability to connect using SSL. If you can’t view this website, SSL problems are likely to blame.
For Internet Explorer read this article.
If you have a firewall, make sure that it allows communication over port 443. Consult your firewall documentation or system administrator if you do not know how to check for this.