Wizard Pages - Application Ids

Application Id

The application id is a unique text string that identifies the installed program. When you make a normal installation of your executable installer it will create an entry in the "Add or Remove Programs" list under the control panel. Information about each installed program is stored in the computer's registry database. Each program has an entry under a unique application id.

When wrapping an executable installer in a MSI package it is important to find the correct application id for the program you are trying to wrap. Here are the steps to locate the correct application id for your program.

  1. Run the executable setup as you normally would to install the program.
  2. Click the "Look up" button next to the application id input field.
  3. Select the program from the list of programs.

Using the look up button after installing the program is the most secure way to find the correct application id.

When an MSI package is uninstalled it will use this application id to locate the uninstall information for the wrapped setup program. The registry will hold an uninstall command line. It is required for a setup executable to write this uninstall command line in the registry during the installation. Otherwise, Windows would not be able to uninstall it. This means that your wrapped program will uninstall automatically if you specify the correct application id. It doesn't matter if your original setup was built with Inno Setup, NSIS from Nullsoft or any other installation framework.

The MSI Wrapper is capable of uninstalling more than one application during the uninstall of the MSI package. A list of application identifiers can be specified to achieve this. Identifiers in the list must be separated by the | character such as:

appid1|appid2|appid3

Upgrade Code

Another important id is the upgrade code. All programs installed using the Windows Installer must have an upgrade code. This code is used when you are trying to install a new version of a program that already exists on the computer. It will use the upgrade code to determine if the program is already installed and select the proper actions based on this. You choose the upgrade code yourself. It is a GUID and you can use the "Create New" button to generate one if you don't have one already.

Please keep in mind that it is important that you use the same upgrade code if you create an MSI package for a newer version of a program that you already have an MSI package for.