Restoring MS-DOS System Files
You cannot restore system files without having first created
the backup diskettes. If your system is down, you cannot
create these diskettes. It is very important to create
backup system diskettes as soon as possible after the
purchase of your computer. Refer to Chapter 1, Creating
Back Up System Diskettes.
The MS-DOS files COMMAND.COM, IO.SYS, EXTMSDOS.SYS, and
MSDOS.SYS are necessary for the operation of your
computer. If any of these files is accidentally deleted or
modified, your computer will not function as designed. This
section describes the procedure for restoring these files
without affecting the applications and data files that may
be on your hard drive.
If you need more information, see the MS-DOS User’s Guide
and Reference.
nNote: IO.SYS, EXTMSDOS.SYS, and MSDOS.SYS are hidden
files. You will not see these files if you view a directory of
drive C using the DIR command.
If COMMAND.COM is Missing
If COMMAND.COM is missing from your hard disk, the screen
displays this message during the boot process:
Bad or missing Command Interpreter
The computer then becomes inactive. Complete the steps in
the next section to restore COMMAND.COM to your hard
disk.
If .SYS Files are Missing
If the IO.SYS, EXTMSDOS.SYS, and/or the MSDOS.SYS files
are missing from your hard disk, the screen displays the
following message during the boot process:
Restoring MS-DOS System Files
2-16 Installing and Using Applications