AhnLab Online Security - FAQ


Error Description: "Installation failed due to an error. Click Yes to resolve this problem."


  • AhnLab Online Security was unable to establish a connection with the authentication server or the update server.
    You may need to change the network settings on your computer.
  • For tightened security, AhnLab Online Security verifies the product each time it runs in order to restore any modified or damaged files, and attempts to perform udpates when the latest security patches become available.
  • The running and verification of the product is performed through the authentication server and update server. Therefore, a connection is required with those servers for normal operations.
  •   Solution
    Click on each of the following six links to see if you can access the pages or download files from the pages.
    [Link 1]
    [Link 2]
    [Link 3]
    [Link 4]
    [Link 5]
    [Link 6]

    If you can download files or see the AhnLab Authentication Server Connection : SUCCESS message without a problem, start the Internet Exporer, go to Tools --> Internet Options --> Advanced, select "Use HTTP 1.1 through proxy connection" and try again.
    When you cannot download files or connet to the AhnLab Authentication Server:
  • If you are using a personal firewall, disable the firewall and try again.
  • If you are using an anti-virus program, disable the program and try again.
  • If you are using a computer inside a company network and the problem persists, report it to your company's network staff for improved network connections.
  • If you are using a router, please change the settings or remove the router and try again.

  • If you are living other than South Korea and cannot connect to Link 2, 3 or the connection speed is slow, please click the link below to install the Hotfix.
    Please follow Step 3. before you install the Hotfix.
    If you live in South Korea, please do not install the Hotfix.