Before installing MOM2005 Agent, make sure Windows Installer 3.1 is installed. I just installed an agent on Windows 2000 server with old version of windows installer and saw this error;
The MOM Server detected that remote computer <FQDN>has older version of Windows Installer installed. Please update to Windows Installer 3.1 version.Please refer to release notes for more details.
Error Code: -2147023283
Error Description: This installation package cannot be installed by the Windows Installer service. You must install a Windows service pack that contains a newer version of the Windows Installer service.