' IOMode Enum
Const ForReading   = 1
Const ForWriting   = 2
Const ForAppending = 8

Dim objFSO
Dim objFile

Dim boolFound
…


Set objFSO = WScript.CreateObject("Scripting.FileSystemObject")

For Each objFile In objFSO.GetFolder(strSource).Files
    With objFSO.OpenTextFile(objFile, ForReading)
        boolFound = False
        
        Do Until .AtEndOfStream
            strLine = .ReadLine()
            
            If InStr(1, strLine, word) <> 0 Then
                boolFound = True
                
                Exit Do
            End If
        Loop
        
        .Close
    End With
    
    If boolFound Then
        With objFSO.OpenTextFile(objFile, ForAppending)
            .WriteLine("<!--OK-->")
            .Close
        End With
    End If
Next

If InStr(1, sw, word) <> 0 Then
file1.close
Set file1 = objFSO.OpenTextFile(objFile, 8, False)
file1.WriteLine("<!--OK-->")

Set objFSO = CreateObject("Scripting.FileSystemObject")
Set file2 = objFSO.OpenTextFile(file, 2, True) 

For Each objFile In objFSO.GetFolder(strSource).Files        
Set file1 = objFSO.OpenTextFile(objFile, 1, False)

While Not file1.AtEndOfStream
sw = file1.ReadLine()

If InStr(1, sw, word) <> 0 Then
Set file1 = objFSO.OpenTextFile(objFile, 8, False)
file1.WriteLine("<!--OK-->")
End If
  
Wend

file1.close
Next