Connected to Internet, but Internet Explorer and Firefox do not work.

hmmmm, lets try resetting the Winsock

When Winsock corrupts, the networking errors that you may face include unable to surf the Internet with “Page cannot be displayed” error message in Internet Explorer

or AOL even though the DSL/ADSL/cable Internet connection is connected. Sometimes, Windows Firewall/Internet Connection

Sharing (ICS) service is terminated as well.

1. Click on Start button.
2. Type Cmd in the Start Search text box
   
   .
3. Press Ctrl-Shift-Enter keyboard shortcut
   
   to run Command Prompt as Administrator. Allow elevation request.
4. Type netsh winsock reset in the Command Prompt shell, and then press the Enter key.
5. Restart the computer.

What netsh winsock reset command does are it resets Winsock Catalog to a clean state or default configuration. It removes all Winsock LSP (Layered Service Providers) previously installed, including the potential malfunctioned LSP that causes loss of network packets transmission failure. So all previously-installed LSPs must be reinstalled. This command does not affect Winsock Name Space Provider entries.

Note: To check which LSPs installed on your Vista system, use netsh winsock show catalog command.

 

It’s also possible to reset TCP/IP Internet Protocol stack.

Hi harryson996601

I am sorry to hear you are having this issue.  I agree with Windows_Defender that it sounds like your browsers have been hijacked.
I have a suggestion, may not resolve the issue but its something we need to try.

Click on Start
In the Start Search Box type in cmd
Right click on the cmd.exe that appears and left click on Run as administrator
You should come to a black screen (the command prompt)
Here I want you to type the following command   ipconfig /flushdns  (notice there is a space after the word ipconfig)
Press enter after you type in the command
Now type the word exit and press the Enter key

Open either browser and see if you can now Browse the Internet

Its also possible your HOST file has been modified and is causing this issue.  See the link below for information on working with the HOST file.
http://www.microsoft.com/windows/ie/community/columns/ietopten.mspx

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Ken
Microsoft Answers Support Engineer
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