File.Replace的用法解决办法

File.Replace的用法
Private Sub btnCopy_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCopy.Click

        File.Replace("d:ee.txt", "e:ee.txt", "e:e.bak")

        Try
            MessageBox.Show("ok!")
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub
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目的：想要把d:ee.txt替换e:ee.txt，备份文件名为e:e.bak，总是失败
出错提示：未处理 System.IO.IOException
  Message="无法将替换文件移到要被替换的文件。要被替换的文件保持原始名称。
"
  Source="mscorlib"
  StackTrace:
       在 System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
       在 System.IO.__Error.WinIOError()
       在 System.IO.File.Replace(String sourceFileName, String destinationFileName, String destinationBackupFileName, Boolean ignoreMetadataErrors)
       在 System.IO.File.Replace(String sourceFileName, String destinationFileName, String destinationBackupFileName)
       在 filetest.Form4.btnCopy_Click(Object sender, EventArgs e)
       在 System.Windows.Forms.Control.OnClick(EventArgs e)
       在 System.Windows.Forms.Button.OnClick(EventArgs e)
       在 System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       在 System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       在 System.Windows.Forms.Control.WndProc(Message& m)
       在 System.Windows.Forms.ButtonBase.WndProc(Message& m)
       在 System.Windows.Forms.Button.WndProc(Message& m)
       在 System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       在 System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       在 System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       在 System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       在 System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
       在 System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       在 System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       在 System.Windows.Forms.Application.Run(ApplicationContext context)
       在 Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
       在 Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
       在 Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
       在 filetest.My.MyApplication.Main(String[] Args)
       在 System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       在 System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       在 Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       在 System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       在 System.Threading.ThreadHelper.ThreadStart()

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求助，谢谢！
------解决方案--------------------
文件路径都不对，盘符后面没有反斜杠。