A perfect Application should not only to show the output as our requirement, the application should also validated by the developer who developed the application. For web application we can use the controls to validate the web page. But in Window Application there is no available control for validation. We have to write code to perform various validations.Â So friends! How to know that EMail Id that was insert by the user is validate or not? The Email Id called a valid Email Id when it was inserted in the proper expression.This article will show you that how to validate Email Id in Window Application Form.