uses ShellAPI;

// Open the C drive
procedure TForm1.Button1Click(Sender: TObject);
begin
  ShellExecute(Handle, 'open', 'Explorer.exe', 'C:\', nil , SW_SHOWNORMAL);
end;

// turn on my computer
procedure TForm1.Button2Click(Sender: TObject);
begin
  ShellExecute(Handle, 'open', 'Explorer.exe',
    ':: {20D04FE0-3AEA-1069-A2D8-08002B30309D}', nil , SW_SHOWNORMAL);
end;

// Open the explorer
procedure TForm1.Button3Click(Sender: TObject);
begin
  ShellExecute(Handle, 'open', 'Explorer.exe',
    '/e,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}', nil , SW_SHOWNORMAL);
end;