Sub LoopAllExcelFilesInFolder()

Dim wb As Workbook
Dim myPath As String
Dim myFile As String
Dim myExtension As String
Dim FldrPicker As FileDialog

'Optimize Macro Speed
  Application.ScreenUpdating = False
  Application.EnableEvents = False
  Application.Calculation = xlCalculationManual

'Retrieve Target Folder Path From User
  Set FldrPicker = Application.FileDialog(msoFileDialogFolderPicker)

    With FldrPicker
      .Title = "Select A Target Folder"
      .AllowMultiSelect = False
        If .Show <> -1 Then GoTo NextCode
        myPath = .SelectedItems(1) & "\"
    End With

'In Case of Cancel
NextCode:
  myPath = myPath
  If myPath = "" Then GoTo ResetSettings

'Target File Extension (must include wildcard "*")
  myExtension = "*.csv"

'Target Path with Ending Extention
  myFile = Dir(myPath & myExtension)

'Loop through each Excel file in folder
  Do While myFile <> ""
    'Set variable equal to opened workbook
      Set wb = Workbooks.Open(Filename:=myPath & myFile)
    
'XXXXXXXXXXXXXXXXXXXXProgramXXstartsXXXXXXXXXXXXXXXXXXXXXXXXX
Dim i As Integer
Dim j

i = 0
j = 0

    Columns("A:A").Select
    Application.CutCopyMode = False
    Selection.TextToColumns Destination:=Range("A1"), DataType:=xlDelimited, _
        TextQualifier:=xlDoubleQuote, ConsecutiveDelimiter:=False, Tab:=True, _
        Semicolon:=True, Comma:=False, Space:=False, Other:=False, FieldInfo _
        :=Array(Array(1, 1), Array(2, 1)), TrailingMinusNumbers:=True

For i = 19 To 522


 '       If  Then
 '           Rows(i).Delete
 '       End If

    If Cells(i, 4).Value >= Cells(i, 5).Value And Cells(i, 4).Value <= Cells(i, 6).Value Or Cells(i, 4).Value = "0" Or Cells(i, 7).Value = "-" Or Cells(i, 7).Value = "mm" Or Cells(i, 4).Value = "Value" Or Cells(i, 7).Value = "mbar" Or Cells(i, 7).Value = "Grad" Or Cells(i, 7).Value = "ccm/min" Or Cells(i, 6).Value = "" Or Cells(i, 5).Value = "" Or Cells(i, 2).Value = "OP1200OS" Or Cells(i, 2).Value = "OP1200CS" Then
    'Range(Cells(i, 1), Cells(i, 8)).Interior.Color = RGB(0, 255, 0)
        Rows(i).Delete
     ' Or Cells(i, 4).Value = "1.3"   Or Cells(i, 6).Value = ""  Or Cells(i, 5).Value = ""    Or Cells(i, 7).Value = "kN"   Or Cells(i, 7).Value = "Nm"
        
    Else
    
    
    Range(Cells(i, 1), Cells(i, 8)).Interior.Color = RGB(255, 0, 0)
    i = i + 1
    
    
   End If
   
   i = i - 1
        
  '      If Range(Cells(i, 1), Cells(i, 8)).Interior.Color = RGB(0, 255, 0) Or Cells(i, 5).Value = "" Or Cells(i, 6).Value = "" Or Cells(i, 7).Value = "-" Or Cells(i, 4).Value = "Value" Then
   '
    '    End If
   
   j = Cells(i, 1).Value
   
   If j = "time" Then Exit Sub
   If j = 0 Then Exit Sub
   
   
Next i

'XXXXXXXXXXXXXXXXXXXXProgramXXendsXXXXXXXXXXXXXXXXXXXXXXXXX

    'Get next file name
      myFile = Dir
  Loop

'Message Box when tasks are completed
  MsgBox "Task Complete!"

ResetSettings:
  'Reset Macro Optimization Settings
    Application.EnableEvents = True
    Application.Calculation = xlCalculationAutomatic
    Application.ScreenUpdating = True

End Sub