Best Way To Determine If .NET 3.5 Is Installed

Question

I need to programatically determine whether .NET 3.5 is installed. I thought it would be easy:

<% Response.Write(Environment.Version.ToString()); %>
         


        

Answer 1

If you want to require a specific version of .net to be installed and can control the distribution of your application, you should really use ClickOnce. It allows you to specify the minimum required version of the .Net framework that should be installed, and it will only check when it is being installed so that all your subsequent startups are not impeded by an unnecessary check.

Also, with ClickOnce you get updating for free. Why wouldn't somebody want to use it?

To set up a ClickOnce application, just right click on the project within Visual Studio and go to the Publish Settings. This will create a special build of your application that you can place on your website. When users download the program, the installer will check for any prerequisites like .Net for you.