Epson 386/25 - Manual (Page 268)

Type C : and press Enter to log onto the hard disk. If this
works, the next step is to make sure the COMMAND.COM
file is in the root directory of the hard disk. Type DIR and
press Enter.
If COMMAND.COM is in the root directory, use the
MS-DOS COMPARE command to compare the
COMMAND.COM file on your diskette with the
COMMAND.COM file on the hard disk. (See your
MS-DOS Reference Manual for instructions on using
COMPARE.) If the files do not match, use the COPY
command to replace the file on the hard disk with the file
on your diskette. Type the following and press Enter:
COPY A:COMMAND.COM C:
Remove the Startup diskette and press the RESET button to
reset the computer. If the computer loads MS-DOS from the
hard disk, you may have corrected the problem.
4. If the hard disk still does not work, the root directory of your
hard disk may be missing some hidden system files. (Hidden
files are not listed when you use the DIR command.)
Insert the Startup diskette and type A : to log onto
drive A. Then type the following and press Enter to copy
the hidden system files from your Startup diskette to the
root directory of the hard disk:
SYS c:
Remove the Startup diskette and reset the computer to see if
it loads MS-DOS from the hard disk.
5. If you can load MS-DOS from your Startup diskette but you
cannot access data stored on your hard disk, you may have
accidentally repartitioned or reformatted part or all of the
disk.
D-20 Troubleshooting