Hello @Gennady Gurin ,
Welcome to Microsoft Q&A forum.
If the setup file is for the specific Windows Forms application, then it depends on what prerequisites that this application needs. For example, if your WinForm application needs .NET Core and SQL Server to run, then you need to select the corresponding prerequisites.
For your scenario, do you know the detailed version of .NET Framework that your application targets? Generally, when you create a new project, VS will prompt you to select a target framework, and in project property page or in project file(for example, .csproj file), you can also find the information of the target framework. You need to first check the framework that your application targets and then select the corresponding one.
For example:
Best Regards,
Tianyu
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