SMARTDRV

Starts or configures SMARTDrive, which creates a disk cache in 
extended memory. A disk cache can significantly speed up MS-DOS 
disk operations. When used for disk caching, SMARTDrive is 
loaded by using the SMARTDRV command in your AUTOEXEC.BAT file 
or at the command prompt.

Note: Older versions of SMARTDRV (3.0 or earlier) appear as a 
file named SMARTDRV.SYS. The newer versions of SMARTDRV (4.0 or 
later) appear as a file as SMARTDRV.EXE. They have different 
usages: The newer version (in MS-DOS 5.0 or later) should be 
started from a command line or a batch file. The older version 
should be started from CONFIG.SYS using DEVICE command. The 
difference above is very important.

I only talk about newer versions of SMARTDRV here. Newer 
versions of SMARTDRV can also be found under MS-DOS 7.0 ~ 
MS-DOS 8.1 (shipped with Windows 95 ~ Me, better Windows 95 
OSR 2 or later, which supports FAT32).

If you install Windows 9x/NT/2000 from MS-DOS, you can first run 
SMARTDRV to create a large disk cache to speed up the 
installation. For example, if you have memory not less than 
64MB, you can type "SMARTDRV 32768". If you have only 32MB, you can 
type "SMARTDRV 28672". Sometimes the Windows 9x setup program 
may pop up a warning message saying that the setup may not work with 
an unknown disk cache (usually due to a higher version MS-DOS), 
ignore it and go on, because it is clearly claimed in Windows 9x 
SETUP.TXT: Do not use any disk cache utility other than SMARTDRV.
However, the program you are using is SMARTDRV.

For more information, please refer to MS-DOS Help or Windows NT 
command line command help.