Creating an MSI transform (.mst) file with Orca

Orca is a tool that allows you to edit an MSI file’s properties. With Orca, you can easily add customized text, add/remove installation screens, or even change certain conditions contained with the original MSI file.
You can download a copy of Orca from: http://www.technipages.com/download-orca-msi-editor.html.
Steps:

1. Open Orca.
2. Open the original MSI. File > Open > Browse to the MSI > Click Open.
3. Start a new transform. Click on the top “Transform” menu, and select “New Transform”.
4. Make changes. Navigate to a table you want to edit, and modify values.
5. Generate the transform file. Click on the top “Transform” menu, and select “Generate Transform”.
6. Save the transform file. Enter in a name for the transform file, and click “Save”.

You should now have a transform file (.mst) that contains the modifications to the original MSI. Keep in mind that the original MSI has NOT been modified. You will have to apply the transform to the original MSI to have the changes take place.

To run the transform:
In cmd, type:
msiexec /i TRANSFORMS=

For example:
msiexec /i orca.msi TRANSFORMS=transformOrca.mst

this post was copied from Tony's TLE blog post (http://tonyle.ca/blog/?p=33)

and re-posted here for my own reference.