Excel object is not getting removed from task manager

Private Function Export_To_Excel(ByVal I_StrFileName As String, ByVal I_strSheetName As String, ByVal I_strSheetNumber As Integer) As Integer
       Dim dicExcel As New Dictionary(Of Integer, Integer)
       Dim MyExcelProcessId As Integer = 0
       Dim AllProcesses() As Process
       Dim blnFileExist As Boolean
       Dim i As Long
       Dim grdExportGrid As New DataGridView
       Dim dtExport As New DataTable
       Dim iRow As Integer
       Dim ColUpdatedIndex As Integer
       Dim ColAmountIndex As Integer

         Try
          ''CheckForExistingExcellProcesses
           AllProcesses = Process.GetProcessesByName("excel")
           For Each ExcelProcess As Process In AllProcesses
               dicExcel.Add(ExcelProcess.Id, 1)
           Next
           ''CheckForExistingExcellProcesses : End

           oExcel = CreateObject("Excel.Application")
           If Dir(I_StrFileName) <> "" Then
               oExcel.Workbooks.Open(I_StrFileName)
               blnFileExist = True
           Else
               oBook = oExcel.Workbooks.Add
               oSheet = oBook.Worksheets(I_strSheetNumber)
               oSheet.Name = I_strSheetName
           End If

           ''GetTheExcelProcessIdThatUsedByThisInstance
           AllProcesses = Process.GetProcessesByName("excel")
           ' Search For the Right Excel
           For Each ExcelProcess As Process In AllProcesses
               If Not dicExcel Is Nothing Then
                   If dicExcel.ContainsKey(ExcelProcess.Id) = False Then
                       ' This is the Process ID that used by your instance
                       MyExcelProcessId = ExcelProcess.Id
                       Exit For
                   End If
               End If
           Next
           ''GetTheExcelProcessIdThatUsedByThisInstance : End

           With oSheet
               i = 1
               For iCol = 0 To grdAccDetails.Columns.Count - 1
                   If grdAccDetails.Columns(iCol).Visible Then
                       .Cells(1, i) = grdAccDetails.Columns(iCol).HeaderText.Replace(vbCrLf, "")
                       .Cells(1, i).EntireRow.Font.Bold = True
                       .Cells(1, i).Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.White)
                       .Cells(1, i).Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Blue)
                       .Cells(1, i).Borders.Value = True
                       If grdAccDetails.Columns(iCol).HeaderText = "Updated At" Then
                           ColUpdatedIndex = i
                       End If
                       If grdAccDetails.Columns(iCol).HeaderText = "Amount" Then
                           ColAmountIndex = i
                       End If

                       i = i + 1
                   End If
               Next

               For iRow = 0 To grdAccDetails.Rows.Count - 1

                   i = 1
                   For iCol = 0 To grdAccDetails.Columns.Count - 1
                       If grdAccDetails.Columns(iCol).Visible Then
                           If grdAccDetails.Columns(iCol).HeaderText = "Updated At" Then
                               .Cells(iRow + 2, i).numberformat = "dd/mm/yyyy HH:mm:ss"
                           End If
                           If grdAccDetails.Rows(iRow).Cells("Operation").Value = "DELETE" Then
                               .Cells(iRow + 2, i).Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.FromArgb(255, 128, 128))
                           End If
                           If grdAccDetails.Columns(iCol).HeaderText = "Amount" Then
                               .Cells(iRow + 2, i).numberformat = "###,##0.00"
                           End If
                           .Cells(iRow + 2, i).Borders.Value = True
                           .Cells(iRow + 2, i) = grdAccDetails.Rows(iRow).Cells(iCol).Value
                           i = i + 1
                       End If
                       .Cells(iRow + 1, i).EntireColumn.AutoFit()
                   Next iCol
               Next iRow
           End With
oBook.SaveAs(I_StrFileName)

           Dim strMSG As String = "Data exported to " & I_StrFileName & "." & vbCrLf & "Do you want to open it?"
           If MessageBox.Show(strMSG, appname, MessageBoxButtons.YesNo, MessageBoxIcon.Question) = Windows.Forms.DialogResult.Yes Then

               oExcel.visible = True
           Else
               ''KillExcelProcessThatUsedByThisInstance
               AllProcesses = Process.GetProcessesByName("excel")
               For Each ExcelProcess As Process In AllProcesses
                   If ExcelProcess.Id = MyExcelProcessId Then
                       ExcelProcess.Kill()
                       Exit For
                   End If
               Next
               AllProcesses = Nothing
               ''KillExcelProcessThatUsedByThisInstance : End
           End If
           Export_To_Excel = 1
       Catch ex As Exception
           Export_To_Excel = 0
           oSheet = Nothing
           oBook = Nothing
           oExcel.Quit()
           oExcel = Nothing
           GC.Collect()
            End Try
   End Function