How to Fix Windows Live Messenger Error code 800401f3

The following error message with the error code 800401f3 may be displayed on your computer screen when you try to use Windows Live Messenger:

Error 800401f3: The service is temporarily unavailable.

Cause of the Error

This error message may be displayed when one or more of the following conditions are true:

  • Windows Live Messenger service is blocked by a firewall or a proxy server.
  • The Windows Messenger version on your computer is old.
  • The Windows Live Messenger is unable to verify the certificates of some of the required library files.
  • You are not connected to the Internet.
  • There is some problem with the Microsoft Internet Explorer security settings.
  • Required XML Libraries are not registered properly on the system.
  • Incorrect cached DNS settings exist on your PC.
  • Your computer is infected with a spyware.

Resolution Steps

To resolve this problem, perform each of the following steps one by one. After each step, try to connect your Windows Live Messenger.

Step 1: Ensure the Windows Live Messenger service is not blocked by a Firewall or Proxy

If you have firewall installed on your computer, check its settings to ensure that the Windows Messenger service is not blocked by it. If you are on a corporate network, check with your network administrator to see if the Windows Messenger service is blocked on the network or not.

Step 2: Check your Internet connection

The best way to check your Internet connection is to try to open a Web site in your Web browser. If you are unable to access the Internet, check your connection settings or contact your Internet service provider or network administrator for a solution.

Step 3: Ensure that you are using the correct username and password

If the error message generated states that your login username and password is incorrect, then first open the following Web site and try to login to it using your username and password:

If you login successfully, open your Windows Messenger and re-enter the username and password you used to login to the Website to sign in to the messenger.

In case your password is blocked due to multiple incorrect attempts, or you still receive the incorrect username/password message, you may contact the Microsoft Passport support web site for a solution.

Step 4: Ensure that you have the latest version of Windows Messenger on your PC

Error code 800401f3 may be generated if you have an older version of Windows Messenger on your system. If you do not have the latest Windows Live Messenger on your computer, you must download it from the Windows Live Messenger web site and install it on your computer.

To ensure correct installation of the latest version, it is recommended that you first uninstall the existing messenger from your computer. To do this you may use the Add or Remove Programs utility that is shipped with your Windows computer. To ensure a complete removal of older versions from your system, you may also use an efficient third-party program uninstaller, such as Perfect Uninstaller to perform the uninstall.

Step 5: Check the date and time settings of your computer

Double-click on the time that is displayed on the taskbar to open the Date and Time Properties dialog box. Here, ensure that the date and time settings of your computer are correct. Incorrect settings may generate connection errors with Windows Live Messenger.

Step 6: Re-register MSMXL Library

MSMXL library is used to send and receive data when you attempt to sign in to the Windows Live Messenger. To re-register this library, at Start > Run, type and execute the following command:


Step 7: Check Internet Explorer settings

In the Internet Explorer window, do the following:

  1. On the Tools menu, select Internet Options.
  2. On the Contents tab, click Clear SSL State in the Certificates section.
  3. Click OK to close the confirmation message box.
  4. On the Advanced tab, click Restore Defaults.
  5. On the Connections tab, click LAN Settings.
  6. Clear all check boxes on the Local Area Settings (LAN) Settings dialog box and then click OK.
  7. Exit Internet Options dialog box and then ensure that you can access the Internet.

Step 8: Re-register security DLL files

At Start >Run, run the following commands one by one to re-register security DLL files on your system.


Step 9: Delete the Contact Cache Folder

  1. Open Windows Explorer.
  2. Change its settings to show hidden files and folders and display extensions of known file types.
  3. Navigate to the following folder:

C:\Documents and Settings \ WindowsLiveUsername \Contacts\ WindowsLiveEmail

  1. Delete all files in this folder.
  2. Next, navigate to the following folder:

C:\Documents and Settings\ WindowsLiveUsername\Local Settings\Application Data\Microsoft\Windows Live Contacts\ WindowsLiveEmail.

Step 10: Check your system for spyware infections

Spyware infections may also prevent you from logging on to your Windows Live Messenger. Use a reliable antispyware tool, such as the Spyware Cease to thoroughly scan your system and system registry and weed out any malicious spyware and adware files from it.