No accessible 'Main' method with an appropriate signature was found in 'Exercise_6_11

I am trying to write a Windows Application but VB.NET says that Command line applications must have a Sub Main defined. But I don't want a command line application! The error message is: "No accessible 'Main' method with an appropriate signature was found in 'Exercise_6_11.PrintSquare'."
:confused:

If you don't want a command line application, you need to start a new project and select Windows Form type of project.