[DotNetDevelopment] Closing Single Instance Application with System.Diagnostics.Process.Close

[Tom C]

I have a single instance application that will not close with the
following code. It just ignores the close command. Anyone have any
ideas why or what I can do to force the application to close?

  testInstances = System.Diagnostics.Process.GetProcessesByName
(processName)
                For z As Integer = 1 To 5
                    If testInstances.Length > 0I Then
                        For i As Integer = testInstances.Length - 1I
To 0I Step -1
                            Dim instance As System.Diagnostics.Process
= testInstances(i)
                            instance.WaitForExit(1000)
                            instance.Close()
                        Next
                        testInstances =
System.Diagnostics.Process.GetProcessesByName(processName)
                    Else
                        Exit For
                    End If
                Next