Office automation: Converting doc to docx

 
[ConversionOptions] section.
[ConversionOptions]
; FullUpgradeOnOpen: if set to 1, Word documents will be fully converted to the OpenXML format
;                    if set to 0 (default), Word documents will be saved in the OpenXML format in compatibility mode
; Not applicable to Excel or PowerPoint files.
FullUpgradeOnOpen=0
 
[FoldersToConvert]
; The Converter will attempt to convert all supported files in the specified folders
; (do not include if specifying FileListFolder)
;fldr=C:\Documents and Settings\Administrator\My Documents
fldr=c:\abc
 

 
using Word = Microsoft.Office.Interop.Word;
using System.Reflection;
using System.IO;
class Program
{
    static void Main(string[] args)
    {
        Word._Application application = new Word.Application();
        object missing = Missing.Value;
        object fileformat = Word.WdSaveFormat.wdFormatXMLDocument;
        DirectoryInfo directory = new DirectoryInfo(@"c:\abc");
        foreach (FileInfo file in directory.GetFiles("*.doc", SearchOption.AllDirectories))
        {
            if (file.Extension.ToLower() == ".doc")
            {
                object filename = file.FullName;
                object newfilename = file.FullName.ToLower().Replace(".doc", ".docx");
                Word._Document document = application.Documents.Open(ref filename,
                    ref missing, ref missing, ref missing, ref missing, ref missing,
                    ref missing, ref missing, ref missing, ref missing, ref missing,
                    ref missing, ref missing, ref missing, ref missing, ref missing);
                document.Convert();
                document.SaveAs(ref newfilename, ref fileformat, ref missing, ref missing,
                    ref missing, ref missing, ref missing, ref missing,
                    ref missing, ref missing, ref missing, ref missing,
                    ref missing, ref missing, ref missing, ref missing);
                document.Close(ref missing, ref missing, ref missing);
                document = null;
            }
        }
        application.Quit(ref missing, ref missing, ref missing);
        application = null;
    }
}