How do I programmatically add a folder to the user's Favorites (in Windows Explorer)?

I am looking for a way to programmatically add a folder to the Favorit开发者_开发知识库es in Windows Explorer. Its Windows Explorer specific and based around this project: http://www.codeproject.com/Tips/132804/Open-folders-using-a-Run-Command

So far I've tried Process Monitor and searching the registry, but I can't seem to find my Windows Explorer Favourites in regedit.

Instead of reading the registry, you can do the following:

string favoritesFolder = 
    Environment.GetFolderPath(Environment.SpecialFolder.Favorites);

P.S.: Make sure to check out @bsegraves' solution, which I think is far better than mine.

I'm not sure if this is what you're looking for, but I think the favorite folder can be found through the following registry value:

HKEY_CURRENT_USER\
  Software\
    Microsoft\
      Windows\
        CurrentVersion\
          Explorer\
            User Shell Folders\
              Favorites

You should be able to retrieve this folder name with the following code:

using Microsoft.Win32;
...

RegistryKey topLevel = Registry.CurrentUser;
RegistryKey key = topLevel.OpenSubKey(
    @"Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders",
    true);

string favoriteFolder = key.GetValue("Favorites").ToString();

It's then only a matter of creating a link, or document, in the specified folder.

(Take note that this key's value might be something like %USERPROFILE%\Favorites; the environment variable should automatically get expanded by the .GetValue(..) method invoked above.)

For Windows 8 this location has been changed to %USERPROFILE%\Links. Please refer to this answer.

Starting from Vista FOLDERID_Links const was added. It points to Favorites of Windows explorer. My code (Delphi, but the main idea is visible):

procedure AddFileObjectToFavorites(AParent: HWND; const AObjectFileName: UnicodeString);

  function GetFavorites: PItemIDList;
  begin
    if IsWindowsVistaOrLater then
      OleCheck(SHGetKnownFolderIDList(FOLDERID_Links, 0, 0, Result))
    else
      OleCheck(SHGetFolderLocation(AParent, CSIDL_FAVORITES, 0, 0, Result));
  end;

var
  Desktop: IShellFolder;
  Eaten: DWORD;
  Attr: DWORD;
  ObjectIDList: PItemIDList;
  ObjectParentFolder: IShellFolder;
  ObjectChildIDList: PItemIDList;
  LinksIDList: PItemIDList;
  LinksParentFolder: IShellFolder;
  LinksChildIDList: PItemIDList;
  DataObject: IDataObject;
  LinksDropTarget: IDropTarget;
  Effect: Integer;
begin
  OleCheck(SHGetDesktopFolder(Desktop));
  try
    Attr := 0;
    OleCheck(Desktop.ParseDisplayName(AParent, nil, PWideChar(AObjectFileName), Eaten, ObjectIDList, Attr));
    try
      SHBindToParent(ObjectIDList, IShellFolder, Pointer(ObjectParentFolder), ObjectChildIDList);
      try
        LinksIDList := GetFavorites;
        try
          OleCheck(SHBindToParent(LinksIDList, IShellFolder, Pointer(LinksParentFolder), LinksChildIDList));
          try
            OleCheck(LinksParentFolder.GetUIObjectOf(AParent, 1, LinksChildIDList, IDropTarget, nil, LinksDropTarget));
            try
              OleCheck(ObjectParentFolder.GetUIObjectOf(AParent, 1, ObjectChildIDList, IDataObject, nil, DataObject));
              try
                Effect := DROPEFFECT_LINK;
                OleCheck(LinksDropTarget.DragEnter(DataObject, 0, Point(0, 0), Effect));
                if Effect and DROPEFFECT_LINK = 0 then
                  begin
                    OleCheck(LinksDropTarget.DragLeave);
                    raise Exception.Create('Cannot drop');
                  end;
                Effect := DROPEFFECT_LINK;
                OleCheck(LinksDropTarget.Drop(DataObject, 0, Point(0, 0), Effect));
              finally
                DataObject := nil;
              end;
            finally
              LinksDropTarget := nil;
            end;
          finally
            LinksParentFolder := nil;
          end;
        finally
          CoTaskMemFree(LinksIDList);
        end;
      finally
        ObjectParentFolder := nil;
      end;
    finally
      CoTaskMemFree(ObjectIDList);
    end;
  finally
    Desktop := nil;
  end;
end;