I will start developing a program with C # using WinForms (Basic Agenda with MySQL) and it is my question to use framework .
This program may be available on other computers and I do not know which Windows might be installed.
What aspects should I look into?
What's best for you, only you can say. I'd always prefer to use the most current one, in case it's the .NET Framework 4.6.2. I have a question about the versions (which by the way I need to update).
If you do everything right in the installation, the .NET Framework required for your application will be installed or updated.
No matter what you use, I see no reason to use an older one. But you might know something I do not know. You may decide that you want to use only .NET already installed. There you have to see which is the oldest computer that will use it and use in your application the version that comes with this Windows. I would not recommend this. You have a table with the versions that come with Windows .
Note that there are other implementations of CLR . Has Mono, has .NET for other device types, has the .NET Core and .NET Native . For WinForms the ideal is to use the "normal" .NET Framework.
In addition to WinForms you can use WPF and UWP (the latter can be used as the .NET Core that does not need to install anything).
Each has its advantages and disadvantages. None is the right one. It depends on your need. All of them can still be used, even if it has no evolution, they are still officially supported.
As a developer, the least you should know is the target ( target ) for which the project will be built. Establish your requirements yourself.
The most obvious is to provide compatibility for the latest and most user-friendly versions to the environment where you want to distribute the application. Generally speaking, the target can currently be from Windows 7. If it "works" under Windows7, it is likely to "work well" under Windows 10, for example, depending on the features you use. Usually the IDE you use asks you to set a target (build target)
Basic steps in the MSDN documentation: link
