Problem installing/uninstalling MSN Messenger

Normally after updating Windows Live Messenger, it is needed that you uninstall the current version in order to use updated version.
However, it is sometimes impossible to uninstall the old version, or even reinstall a new version.

Indeed, Windows reports an error or warning that <MsnMsgs.msiwas not found>.

• Examples of error codes on install or uninstall WLM (or MSN Messenger)
  • 1603: Fatal error during installation.
  • 1604: Installation suspended, not ended.
  • 1605: This action is only valid for products currently installed.
  • 1635: Unable to open this patch package.Verify that the patch package exists and that you can access it, or contact the application vendor to verify that

this is a valid Windows Installer patch package.

• • 1636: Unable to open this patch package. Contact the application vendor to verify that this is a valid Windows Installer patch package.
  • 1637: This patch package is not executable by the Windows Installer service. You must install a service pack that contains a version of Windows Installer service later.

Download and install Windows Installer CleanUp

To handle this kind of problem simply download and run the "Windows Installer CleanUp". Visit the Microsoft site for downloading.
http://support.microsoft.com/kb/290301

• Exit the program WLM / MSN during the procedure.
• Download and install Windows Installer CleanUp.
• Save it to your programs files before you run. it
• Open it from start menu/ program filess.
• A window displaying the list of programs used by "Windows Installer" is displayed.
• Select the program, that is causing trouble : In our case MSN / WLM
• Then click "Remove" and then "Exit".
• Restart the computer for the changes to take effect.

After this, you can now uninstall your current version via the control panel, then install your new version!