Unable to install application

Question

I have two applications in VB.NET. When I was implementing second project I just copy & paste first one and made some changes because they are similar. In each solution I have also setup project for installation. Now when I want to install second application with setup, I can't because I get this message:

Unable to install because newer version of this product is already installed.

So I have two independent applications (each has different version number, title, product name). The same attributes are only Company, Copyright and Trademark. But to OS it looks like these two applications are the same but only different versions.

My question is how can I distinguish these applications to look like different independent applications? What attribute during installation is important to find out if this application is already installed? Thank you guys!

Answer 1

Just a quick guess - you may want to check that the two projects don't have the same GUID (you'll probably need to open the project files in a text editor to check this).

I don't know for sure if the installer package checks this, but definitely a potential candidate for causing this behaviour.