snAppShot Application Packages versus .MSI Files

Now that the creation of Application object packages using snAppShot has been discussed, it is useful to know how they compare to Microsoft Windows installer (.MSI) package files. The files involved are described as follows:

• .MSI Files An .MSI file is a storage file containing the instructions and data required to install an application. .MSI files are used by the Microsoft Windows Installer to deploy and install applications to computers with 32-bit versions of Windows on them.

• .MSM Files A merge module (.MSM) file, referred to as merge package file, is a single package that includes all files, Registry changes, and setup logic to install a shared component. Merge modules are contained inside .MSI files.

How .MSI Files Are Created

The information .MSI files contain depends on how they are created. The following sections describe the ways that .MSI files are typically created.

Development Tool Method

The most complete way of creating .MSI files is by using development tools to create .MSM and .MSI files, and then configuring them with the files, Registry changes, resources, and logic to perform a complete install of the application.

This method is preferred by most application developers, because it gives them the greatest control over how and what information and logic actually goes into the .MSI file.

Discovery Method

The discovery method of creating .MSI files is very similar to the way snAppShot creates its Application object templates. The discovery method works by using a double discovery process to accumulate changes made by an install. Most third-party application installs are created by this method. The following steps describe how this method is accomplished:

1. Begin with a clean PC, or one that is representative of the computers in your network.

2. Start Discover to take a picture of the representative PC's software configuration. This is the "before" snapshot.

3. Install a program on the PC on which you took the before snapshot.

4. Reboot the PC.

5. Run the new program to verify that it works.

6. Quit the program.

7. Start Discover and take an "after" snapshot of the PC's new configuration. Discover compares the before and after snapshots and notes the changes. It creates a Microsoft installer package with information about how to install that program on such a PC in the future.

8. Clean the reference computer to prepare to run Discover again.

How Do .MSI Files Work with ZENworks for Desktops?

Now that you understand what .MSI files are and how they are created, you need to understand what role they can play in creating Application objects, instead of using .AOT or .AXT files.

The ZENworks snap-ins to ConsoleOne enable you to use .MSI files to create Application objects in exactly the same way that .AOT or .AXT files are used. Therefore, if an .MSI file is already available for an Application object, you can save yourself time and effort by simply using the .MSI file to create the Application object (discussed in the next chapter).

Using ZENworks, you can also apply .MST files along with the .MSI files to your desktops.