Application relaunches outside of program!

I've tried to do this code below that runs on form load:

 
Declare Auto Function SetParent Lib "user32.dll" (ByVal hWndChild As IntPtr, ByVal hWndNewParent As IntPtr) As Integer
    Declare Auto Function SendMessage Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
    Private Const WM_SYSCOMMAND As Integer = 274
    Private Const SC_MAXIMIZE As Integer = 61488
    Dim proc As Process
    Private Sub LessonMap_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        proc = Process.Start("C:\Program Files (x86)\CoreUIPtest\Launcher.exe")
        proc.WaitForInputIdle()

        SetParent(proc.MainWindowHandle, Panel1.Handle)
        SendMessage(proc.MainWindowHandle, WM_SYSCOMMAND, SC_MAXIMIZE, 0)
    End Sub

The program has a splash form, and when the form disappears, the program opens outside of the program, but the splash form loads inside the application, can anyone help? This is a problem and I need to finish it soon.