How to check if a specific software is already installed

[cogs33]

Hi all,

What would be the correct way to check if another software (same publisher) is already installed and then refuse to proceed with the installation?

Rationale: The product about to be installed would irreversibly alter existing installations of several predecessor products, so the installer must make sure no such conflict existis before installing. A warning message is supposed to appear, warning the user to uninstall said products first, or at least make a system backup.

As far as I understand, a Launch Condition can accomplish this?
I find the dialog for adding launch conditions a bit confusing.
How would an expression for this look like?

[Liviu]

Hello,

You can achieve this by using a Search and use the property as a custom condition in the Launch Conditions page.

Let's say we do not want to install our application when Notepad++ is installed. In order to achieve this, follow these steps:

1. In the Search page create a new search. For example we can check if the registry key exists:

search.png (20.69 KiB) Viewed 5029 times

2. In the Launch Conditions page click on the Custom tab and add the following condition: NOT RESULT_PROPERTY

Attached you can find a sample project.

You can also use a ProductVersion search since you know the Product Code of your other applications:

productversion search.png (29.88 KiB) Viewed 5028 times

You can also have a look on the Custom launch condition using extended search for registry key. forum thread.

Hope this helps!

Best regards,
Liviu