Closing a specific file

[Keala]

I have folder with many files, which the code below is applied on.
So the process is to select the folder which have the files. The code open first *.txt file in excel, do some calculations save the *.txt file to *.xls file (Waveform_Freq-140.0_PC-10.0_KKC-2.0_180817-143116), copy/paste calculation result to a different open *.xls file (Joined_PC_Level_I) and loop this through the entire folder. But it keep all opened *.xls files, which the calculations was done on open (Waveform_Freq-140.0_PC-10.0_KKC-2.0_180817-143116).
How do I do to close the *.xls file which the recent calculations were done on. So populate all the necessary fields in the Joined_PC_Level_I.xlsx but have closed all the *.xlsx files which was opened and calculated one by one. (the memory gets full to have many excel files open at the same time and then the code pop a alert code and stops)

I have tried with some different options but nothing do the work. I have marked the lines which I think need to be updated for doing what I want to do.

Thank you for any suggestions and improvments

Sub Macro1openwaveformfiles()
'
' Macro1 Macro
'
' Keyboard Shortcut: Ctrl+r
'


screenUpdateState = Application.ScreenUpdating
statusBarState = Application.DisplayStatusBar
calcState = Application.Calculation
eventsState = Application.EnableEvents
displayPageBreakState = ActiveSheet.DisplayPageBreaks 'note this is a sheet-level setting
'turn off some Excel functionality so your code runs faster
Application.ScreenUpdating = False
Application.DisplayStatusBar = False
Application.Calculation = xlCalculationManual
Application.EnableEvents = False
ActiveSheet.DisplayPageBreaks = False 'note this is a sheet-level setting


Dim MyFolder As String
 Dim myFile As String
 Dim folderName As String
 Dim Workbook As String
 Dim filename As String
 Dim c As Long
 Dim k As Long
 Dim j As Long
 Dim p As Long
 Dim d As Long
 
 c = 4
 j = 4
 k = 2
 p = 3
 d = 3
 
 With Application.FileDialog(msoFileDialogFolderPicker)
 .AllowMultiSelect = False
 If .Show = -1 Then


 folderName = .SelectedItems(1)
 End If
 End With


 myFile = Dir(folderName & "\*.txt")
 
 Do While myFile <> ""
 Workbooks.OpenText filename:=folderName & "\" & myFile, Origin:=437, StartRow:=1, DataType:=xlDelimited, TextQualifier:= _
        xlDoubleQuote, ConsecutiveDelimiter:=False, Tab:=True, Semicolon:=False, _
        Comma:=False, Space:=False, Other:=False, FieldInfo:=Array(1, 1), _
        TrailingMinusNumbers:=True
 Cells.Select
    Selection.Replace What:=".", Replacement:=".", LookAt:=xlPart, _
    SearchOrder:=xlByRows, MatchCase:=False, SearchFormat:=False, _
    ReplaceFormat:=False
'ActiveWorkbook.SaveAs Filename:=folderName & "\" & Replace(myfile, ".txt", ".xlsx"), FileFormat:=xlOpenXMLWorkbook, CreateBackup:=False
 
 Range("A300038").Select
    ActiveCell.FormulaR1C1 = "Max"
    Range("A300039").Select
    ActiveCell.FormulaR1C1 = "Min"
    Range("B300038").Select
    ActiveCell.FormulaR1C1 = "=MAX(R[-300003]C:R[-1]C)"
    Range("B300038").Select
    Selection.AutoFill Destination:=Range("B300038:C300038"), Type:= _
        xlFillDefault
    Range("B300038:C300038").Select
    Selection.AutoFill Destination:=Range("B300038:C300039"), Type:= _
        xlFillDefault
    Range("B300038:C300039").Select
    Range("B300039").Select
    ActiveCell.FormulaR1C1 = "=MIN(R[-300003]C:R[-1]C)"
    Range("C300039").Select
    ActiveCell.FormulaR1C1 = "=MIN(R[-300003]C:R[-1]C)"
    Range("C300040").Select
    ActiveWindow.SmallScroll Down:=12
    Range("B300040").Select
    Application.CutCopyMode = False
    ActiveCell.FormulaR1C1 = "=R[-2]C-R[-1]C"
    Range("B300040").Select
    Selection.AutoFill Destination:=Range("B300040:C300040"), Type:= _
        xlFillDefault
    Range("B300040:C300040").Select
    Range("A300040").Select
    ActiveCell.FormulaR1C1 = "Diff"
    Range("A300041").Select
    filename = ActiveWorkbook.Name
 ActiveWorkbook.SaveAs filename:=folderName & "\" & Replace(myFile, ".txt", ".xlsx"), FileFormat:=xlOpenXMLWorkbook, CreateBackup:=False
  
    Range("B300038:B300040").Copy
    Windows("Joined_DC_Level_I.xlsx").Activate
    Cells(j, c).Select
       
    Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
    p = j - 1
    Cells(p, c).Select
    
    ActiveCell.FormulaR1C1 = filename
    d = j - 2
    Cells(d, c).Select
    ActiveCell.FormulaR1C1 = "DC" & k
    c = c + 1
    k = k + 2
    
    If k = 18 Then
     k = 2
    End If
    
    If c = 12 Then
     c = 4
     j = j + 5
    End If
    
    'ThisWorkbook.SaveAs
    ActiveWorkbook.Save
[SIZE=4][COLOR=#00ff00]    Application.Workbooks("filename").Activate[/COLOR][/SIZE]
[SIZE=4][COLOR=#00ff00]    ActiveWorkbook.Close SaveChanges:=True[/COLOR][/SIZE]
  
 'ActiveWorkbook.SaveAs Filename:=folderName & "\" & Replace(myfile, ".txt", ".xlsx"), FileFormat:=xlOpenXMLWorkbook, CreateBackup:=False
 'wb.Close False
 'Ensure Workbook has closed before moving on to next line of code
  DoEvents


 'Get next file name
  myFile = Dir
 Loop
 
 'ThisWorkbook.SaveAs True
    For Each wb In Workbooks
        If wb.Name <> ThisWorkbook.Name Then
            'wb.SaveAs Filename:=Path & wb.Name
            ', FileFormat:=51
           wb.Close False
        End If
    Next wb
    'ThisWorkbook.Close False
 
 Application.ScreenUpdating = screenUpdateState


Application.DisplayStatusBar = statusBarState


Application.Calculation = calcState


Application.EnableEvents = eventsState


ActiveSheet.DisplayPageBreaks = displayPageBreaksState 'note this is a sheet-level setting
 
 
 
End Sub