With .Workbooks(.Workbooks.Count)
For i = 1 To .Worksheets.Count
WrksheetName = .Worksheets(i).Name
DoCmd.TransferSpreadsheet (acImport), acSpreadsheetTypeExcel97, "Testing Tab", OpenFile.lpstrFile, False, "Access"
Next i
End With
replace with
DoCmd.TransferSpreadsheet (acImport)...