Microsoft® Windows® Installer manages the installation and updating of applications, such as Microsoft® Office®. Microsoft recommends upgrading Windows Installer to version 2.0 before applying updates to applications.
For more information about this update, read Microsoft Knowledge Base (KB) Article Q292539. (This site is in English.)
If you are using Windows 2000 and upgraded to Windows Installer 2.0 before March 2002, Microsoft recommends installing this update. The previous version did not install MSPATCHA.DLL correctly. For more information, read Microsoft KB article Q319388 (This site is in English.)
For more information about the issues addressed by Windows Installer 2.0, read the following Microsoft KB Articles: