Using Calc.exe File In .net?

I want to use calc.exe file in my vb .net program. I was trying this code but it not works as what I want.

Private Sub CalculatorToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CalculatorToolStripMenuItem.Click

Dim startInfo As System.Diagnostics.ProcessStartInfo Dim p As New System.Diagnostics.Process

startInfo = New System.Diagnostics.ProcessStartInfo("calc.exe")
p.StartInfo = startInfo
p.Start()
p.WaitForExit()

When I click the menu to use the calculator, my system seem to hang and the background process is stopped.

What I want is, when I click to use the calculator, the background process is not stop. I only want we cannot touch the form at the back, I meant we cannot click the function at the back form untill the calculator is close. The calculator also should locate at the top of the form and cannot be minimized.