You can make a form as top most form in two ways, either at runtime or at design-time.To make a form the top-most form in a Windows Forms application at design time, you need to set TopMost property to True in Properties windows. At Runtime:Private Form.TopMost = True
Make a Form as top most Form in VB.NET
Make my form a default form at start-up instead for Form1 in VB.NET