You have to be very careful with Excel objects and fully qualify each
refernce.  Access will create another instance if it can't figure out which
object another object belongs to.  This will cause problems with Excel
processes still running.  You will see them on the Processes pane of Task
Manager, not the Application pane.

See if these changes do any good.
Dim objXL As Object
Dim xlBook1 as Object
Dim xlBook2 as Object
Set objXL = CreateObject("Excel.Application")
Set xlBook1 = objXL.Workbooks.Open (objXL.LibraryPath
& "\AtData.XLA") '.RunAutoMacros 1
Set XlBook2 =  objXL.Workbooks.Open "C:\AlkyLabData.xls"
objXL.Visible = False
xlbook1.Close
xlbook2.Close
objXL.Quit
Set objXL = Nothing
Set xlBook1 = Nothing
Set xlBook2 = Nothing

DoCmd.TransferSpreadsheet , , "TestingImportData2", "C:\AlkyLabData.xls", True

Me.Requery
DoCmd.GoToRecord , , acLast

Also, copied from VB Editor Help is some code that makes this pretty
straightforward.  Copy this into a standard module.  I call mine
modExcelRoutines

Option Compare Database
Option Explicit

' Declare necessary API routines:
Declare Function FindWindow Lib "user32" Alias _
"FindWindowA" (ByVal lpClassName As String, _
                   ByVal lpWindowName As Long) As Long

Declare Function SendMessage Lib "user32" Alias _
"SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, _
                   ByVal wParam As Long, _
                   ByVal lParam As Long) As Long

Sub GetExcel()
   Dim MyXL As Object    ' Variable to hold reference
                               ' to Microsoft Excel.
   Dim ExcelWasNotRunning As Boolean    ' Flag for final release.

' Test to see if there is a copy of Microsoft Excel already running.
   On Error Resume Next    ' Defer error trapping.
' Getobject function called without the first argument returns a
' reference to an instance of the application. If the application isn't
' running, an error occurs.
   Set MyXL = GetObject(, "Excel.Application")
   If Err.Number <> 0 Then ExcelWasNotRunning = True
   Err.Clear    ' Clear Err object in case error occurred.

' Check for Microsoft Excel. If Microsoft Excel is running,
' enter it into the Running Object table.
   DetectExcel

' Set the object variable to reference the file you want to see.
   Set MyXL = GetObject("c:\vb4\MYTEST.XLS")

' Show Microsoft Excel through its Application property. Then
' show the actual window containing the file using the Windows
' collection of the MyXL object reference.
   MyXL.Application.Visible = True
   MyXL.Parent.Windows(1).Visible = True
'     Do manipulations of your  file here.
   ' ...
' If this copy of Microsoft Excel was not running when you
' started, close it using the Application property's Quit method.
' Note that when you try to quit Microsoft Excel, the
' title bar blinks and a message is displayed asking if you
' want to save any loaded files.
   If ExcelWasNotRunning = True Then
       MyXL.Application.Quit
   End If

   Set MyXL = Nothing    ' Release reference to the
                               ' application and spreadsheet.
End Sub

Sub DetectExcel()
' Procedure dectects a running Excel and registers it.
   Const WM_USER = 1024
   Dim hWnd As Long
' If Excel is running this API call returns its handle.
   hWnd = FindWindow("XLMAIN", 0)
   If hWnd = 0 Then    ' 0 means Excel not running.
       Exit Sub
   Else
   ' Excel is running so use the SendMessage API
   ' function to enter it in the Running Object Table.
       SendMessage hWnd, WM_USER + 18, 0, 0
   End If
End Sub

In Excel VBA Help, i would strongly recommend looking up the entry for
"Addins Collection" object.

Per the Help entry, the proper syntax to add (and install) an add-in is:

       Addins.Add("generic.dll").Installed = True

Please don't just take the above example and try to run with it without
reading the Help entry first.

HTH,