http://www.microsoft.com/downloads/release.asp?ReleaseID=32832

Windows Installer 2.0 Redistributable for Windows NT 4.0 and 2000 

The Microsoft® Windows® Installer is an application installation and configuration service. Instmsi.exe is the redistributable package for installing or upgrading Windows Installer. 
Version - 2.0 
Release Date - 25 Sep 2001 
Estimated Download Size/Time @28.8 - 1,779 kb / 9min 
System Requirements 

Windows Installer 2.0 Redistributable for Windows NT 4.0 and 2000 supports Windows NT 4.0 with Service Pack 6 or later and Windows 2000. Windows XP contains Windows Installer 2.0 and therefore can't be installed or upgraded by this redistributable.

For Windows 95, 98 and ME see "Windows Installer 2.0 Redistributable for Windows 9X" 

Operating System - Windows NT 4.0 & 2000 

Download Now InstMsi.exe - 1,822 Kb 


IMPORTANT DOWNLOAD INSTRUCTIONS 

Double click instmsi.exe.
- Select "Run this Program from its Current Location" to start the installation or upgrade immediately. 
- Select "Save this Program to Disk" to copy the download to your machine for installation at a later time.

For complete information on installing or upgrading Windows installer, including command line options, please see the Windows Installer Software Developers Kits (SDK), available at http://www.microsoft.com/msdownload/platformsdk/sdkupdate