uses
 ActiveX, ShlObj;
procedure TForm1.Button1Click(Sender: TObject);
var
 pShell, ShellFolder: IShellFolder;
 pidl: PITEMIDLIST;
 PMalloc: IMalloc;
 sName: string;
 EnumIDList: IEnumIDList;
 pceltFetched: ULONG;
 lpName: TStrRet;
 slDirectories: TStringList;
begin
 slDirectories := TStringList.Create;
 try
  SHGetDesktopFolder(ShellFolder);
  SHGetSpecialFolderLocation(0,CSIDL_DRIVES, pidl);
  SHGetMalloc(PMalloc);
  ShellFolder.BindToObject(pidl, nil, IID_IShellFolder, Pointer(pShell));
  pShell.EnumObjects(0,SHCONTF_FOLDERS, EnumIDList);
  while EnumIDList.(1,pidl, pceltFetched) = S_ok do
  begin
  pceltFetched := 0;
  lpName.uType := 0;
  pShell.GetDisplayNameOf(pidl, SHGDN_FORPARSING, lpName);
  sName := lpName.pOleStr;
  slDirectories.Add(sName);
  end;
  ListBox1.Items.Assign(sldirectories);
 finally
  pMalloc._Release;
  pMalloc := nil;
  slDirectories.Free;
 end;