Smartdrive (smartdrv.exe)

The smartdrv.exe is an external command available in MSDOS. So whenever you boot with your recovery disk or whenever you don't actually run windows and you are in the command promt, you need to load smartdrv.exe for faster disk access. It will highly improve the speed of searching for files or deleting big directories. After Windows is loaded, such things are handles by the windows itself so you no longer need external programs like smartdrive.