Video Transcript

Hi, this is Jeremy Moskowitz from and today we are going to talk about deploying MST files. What the heck is an MST File? Well it is a Microsoft Transform File and the idea is that, let's say you have deployed your MSI application but maybe it has got too much or too little or it is not configured the way you want. Some applications give you the ability to inject what is called an MST file as sort of a transform over the MSI file. So, what does that mean? That means you are deploying the MSI file you normally get a whole bunch of regular stuff the way the package was intended, but now you are putting this filter on it that lets you change the kinds of things that you can do as a user.

By way of example here you can see I have already deployed this Office version and everything is great here. Now let's go ahead a take a look at an application that lets you create MST files. The trick is that they are very far and few between of third party applications that let you create MST files for their own application. For instance, this is all I know, but here is Office 2003 and I am talking about Office 2003 as an example application, even though it is kind of old.

Here is the idea of the Custom Installation Wizard. The Custom Installation Wizard lets you pick the MSI file that you have, for instance right there, and lets me create a customized transform ability for this. So, I will create a new MST file here and I will give this a new name I will call this Custom1 or something. Now, like I said, this application has twenty-four different screens of fun to play with here. We are not going to go over them, but the point of the story is that you would configure your application the way you wanted it to work and operate that might be different than the defaults. When you click Finish you are saving the MST file out for later use.

Now if we go back to the actual application itself and we click into it, and we have deployed Office, by way of example, and we click on Modifications. This is where you would put MST files, but uh-oh, you have no way to add it. So the idea is that even though you already have that application all ready to go it does not work until you remove the application and redeploy it. We go to New Package here, and I am going to now at this stage, only at the deployment stage, I get a onetime shot for actually using my MST file. I am going to Modifications, click Add, and pick my custom MST which will actually transform that MSI.

So, that is the general way of things. You deploy an MSI file, but before you deploy it you customize and create the MST file which is a filter over that MSI file. Like I said, there are some applications that come with built in MST generators like this older Office version does, but there are also third party repackaging tools that also allow you to create MST files for lots of applications. With that in mind, that is how MST files work and I guess I will talk to you soon on