Loaded file size in memory?

VS 2008, .net 2

Can I find out (some call or something) how much of a file is currently loaded in memory (it's a big file, flash exe projector presentation - 120 Mb and on some computers it takes <2 min) - to use it on Progress Bar with percentage?

Now it's marque Progress Bar till file is completly loaded and started but I prefer Standard with text percentage underneath.

I wonder if it's possible?

Code:

---

...
            Dim myProcess As System.Diagnostics.Process = New System.Diagnostics.Process()
            myProcess.StartInfo.FileName = "F:\Test.exe"
            myProcess.Start()

            ' wait until the program is ready for input
            myProcess.WaitForInputIdle()
'till here is Marque Progress Bar played
... etc         
            Me.Close()

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