Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load If Process.GetProcessesByName(Process.GetCurrentProcess.ProcessName).Length() > 1 Then MsgBox("This is a Single instance Applicaton " & vbNewLine & "* Another Instance is Already Running", MsgBoxStyle.OKOnly, "Single Instance Application") End End If End Sub