Epson CW3S16 Operation Manual page 108

To begin, boot up your system using your MS-DOS as
explained in Chapter 4, "Using MS-DOS.' Then enter this
command:
If the computer responds with:
enter:
If a directory listing is displayed, even if there are no files
shown, it means that your hard disk system has already been
partitioned and formatted. You will see the
COMMAND.COM file at the top of the directory listing if the
MS-DOS active routines have been loaded onto the hard disk.
If your hard disk has been partitioned and formatted, skip this
section on installing your hard disk.
If the computer responded to the A>C: command with:
Invalid drive specification
it means that MS-DOS can't "find" the hard disk drive. This
is either because the drive controller board has been incorrectly
set up, or more likely, the hard disk drive has not yet been
partitioned.
If the computer correctly executed the C: command, but failed
to display a directory, it probably means that the hard disk has
been partitioned, but not yet formatted. The next sections
describe how to partition and format your hard disk system.
Using Your Hard Disk
6-3