IO.File.Delete Random UnauthorizedAccessException - vb.net

Question

I'm using My.Computer.Filesystem.WriteAllBytes to write out an executable stored in my application's resources to it's startup directory. After running the executable, I then delete it. Everything works fine; however, I'll randomly get an UnauthorizedAccessException for no reason. After getting the exception, I can manually delete the file with no problem. Here's the full code:
' Convert MP3
' First, copy out converter
Dim Path = New IO.FileInfo(SoundPath)
Try
My.Computer.FileSystem.WriteAllBytes(Application.StartupPath + "\converter.exe", My.Resources.madplay, False)
Catch ex As Exception
MessageBox.Show(ex.ToString, "Report", MessageBoxButtons.OK)
Exit Sub
End Try
' Set up process
Dim MAD As New Process
' Set process info
Dim output As String = IO.Path.GetFileNameWithoutExtension(Path.FullName) + ".wav"
Dim input As String = Path.FullName
Dim adjust As String = barVolumeAdjust.Value.ToString
Dim hz As String = "15000"
With (MAD.StartInfo)
.FileName = Application.StartupPath + "\converter.exe"
.Arguments = "-v -a " + adjust + " -R " + hz + " -o """ + output + """ """ + input + """"
.UseShellExecute = False
.RedirectStandardInput = True
.RedirectStandardError = True
.RedirectStandardOutput = True
.CreateNoWindow = True
End With
' Start
MAD.Start()
' Update title with output
Dim Line As String = MAD.StandardError.ReadLine
While Not Line Is Nothing
Me.Text = Line
Line = MAD.StandardError.ReadLine
End While
' Stop
MAD.Close()
' Delete MAD
Try
IO.File.Delete(Application.StartupPath + "\converter.exe")
Catch ex As Exception
MessageBox.Show(ex.ToString, "Report", MessageBoxButtons.OK)
End Try
What perplexes me is that I literally just wrote out the executable, and nothing else could possibly be using it. I've checked the file attributes and it's not read-only. My application is also running as an administrator. What could be the problem?

Answer 1

You do not wait for the process to exit, so it is still running when you attempt to delete the file. See Process.WaitForExit

Answer 2

It looks like your using a separate process to write out the file - perhaps this is still using the file when you try to delete.
I suggest catching and handling the exception to get around the problem.