Found this post at MSFN with links to the Microsoft Orca software:

http://www.msfn.org/board/index.php?showtopic … 81&#entry568281

1. Install Orca 2.0.3790: download this CAB [3 MB, right-click to save] = part of Installer SDK 2.0: http://download.microsoft.c […]
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1. Install Orca 2.0.3790:
download this CAB [3 MB, right-click to save] = part of Installer SDK 2.0:
http://download.microsoft.com/download/pla...-common.3.0.cab
Extract Orca_Msi.FD66E721_5AA0_41BC_AA26_1EC8F7FA1175 from CAB -> rename it to orca.msi -> double-click on orca.msi to install Orca -> run orca.exe [usually installed under C:\Program Files\Orca].

2. Install Orca 1.10.1124:
download Installer SDK 1.1:
http://www.microsoft.com/downloads/details...ad-bfc98e3ae4a3
file [7.92 MB, right-click to save]:
http://download.microsoft.com/download/pla...US/IntelSDK.msi
Install IntelSDK.msi -> look under the \Tools subfolder -> should see orca.msi -> double-click on orca.msi to install Orca -> run orca.exe [usually installed under C:\Program Files\Orca9x].

3. Orca 3.1 [part of Installer SDK 3.1] does *not* work with 9x OSes:
http://www.microsoft.com/downloads/details...3E-40C0EC4F68E5

I just checked them all out and can confirm that all downloads have Orca within them. I extacted the Orca.msi's and saved them to a seperate location for easy access.

From the ORCA documentation:

Purpose Orca is a Windows Installer package editor provided as part of the Windows Installer SDK and designed to provide full ac […]
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Purpose
Orca is a Windows Installer package editor provided as part of the Windows Installer SDK and designed to provide full access to the database tables that compose a Windows Installer package. While Orca provides powerful access to all features of the Windows Installer, it is not intended to replace a full-featured package-authoring environment.

Where Applicable

Windows Installer enables the efficient installation and configuration of your products and applications. Orca can be used to create and edit Windows Installer databases. These include installation databases (.msi files), merge modules (.msm files), database patches (.msp files), database transforms (.mst files), validation modules (.cub files), and patch creation (.pcp files.) This document describes features available in Orca 3.0, provided as part of the Windows Installer SDK for the Windows Installer version 3.0. It is capable of creating and editing databases designed to use the new features of Windows Installer version 3.0. Other versions of Orca may differ in appearance, functionality, and behavior. You can use Orca 3.0 to edit packages created with earlier versions of the Windows Installer.

Developer Audience

This documentation is intended for software developers who want to make applications that use Windows Installer. Orca can be obtained by downloading and installing the Windows Installer SDK. It is not possible to download Orca separately. Setup developers that do not require full access to all the features of the Windows Installer should consider using one of the commercially available Windows Installer creation tools available from independent software vendors. In many cases it can be easier to create typical installations using one of these tools than with Orca.exe and the SDK tools.

Run-Time Requirements

The run-time requirements for Orca are the same as for the Windows Installer.

Windows Installer version 2.0 is contained in Microsoft Windows Server 2003 family and Windows XP. This technology is available as a redistributable for Windows Installer version 2.0, from the SDK Update site (http://www.microsoft.com/msdownload/platformsdk/sdkupdate/). Two packages are available at this site. One is for installing or upgrading to Windows Installer version 2.0 on Windows ME, Windows 98, and Windows 95. The other package is for installing or upgrading to Windows Installer version 2.0 on Windows 2000 and Windows NT 4.0. These packages should not be used to install or upgrade Windows Installer version 2.0 on Windows Server 2003 family and Windows XP.

Windows Installer version 3.0 requires Windows Server 2003, Windows XP, or Windows 2000 with Service Pack 3. Windows Installer version 3.0 is planned to be available as a free download shortly after the release of Software Update Services version 2.0.

Orca can be very useful for game related purposes or just general Microsoft installer issues.

For instance my latest use of it was to remove the restriction in Windows Defender that would not allow it to install on Windows 2000. You can also use Orca to do the same thing for game installers that will not install on various version of Windows due to restrictions in the installer.