MS DOS Command: SYS.COM

Reference from Microsoft MS-DOS cmd help

Description

Creates a startup disk by copying hidden MS-DOS system files (IO.SYS and MSDOS.SYS), the MS-DOS command interpreter (COMMAND.COM), and the part of MS-DOS that provides access to compressed drives (DRVSPACE.BIN) to the disk. (SYS copies DRVSPACE.BIN only if the DRVSPACE.BIN file exists in the root directory of the source drive or directory.)

IO.SYS, MSDOS.SYS and DRVSPACE.BIN are hidden files and do not typically appear when you type the DIR command. To see these files, type DIR /A.

Syntax

SYS [drive1:][path] drive2:

Parameters

[drive1:][path]	Specifies the location of the system files. If you do not specify a path, MS-DOS searches the root directory on the current drive for the system files.
drive2:	Specifies the drive to which you want to copy the system files. These files can be copied only to a root directory, not to a subdirectory.

Related Commands

For information about copying files, see the COPY and XCOPY commands.

Remarks

How the SYS command copies files

The SYS command copies the files in the following order: IO.SYS, MSDOS.SYS, COMMAND.COM and DRVSPACE.BIN.

No requirement for contiguous files

MS-DOS no longer requires the two system files to be contiguous. This means that when you want to copy a new version of MS-DOS to a disk containing system files for MS-DOS version 3.3 or earlier, you need not reformat the disk.

Using the SYS command on compressed drives

The SYS command does not work on compressed drives. If drive C is compressed and you need to make your hard disk bootable, use the SYS command on drive C's host drive. (If you are using DriveSpace, to find out which is drive C's host drive, type DRVSPACE /INFO C: at the command prompt.)

Using the SYS command on assigned drives and network drives

The SYS command does not work on drives that have been redirected by using the ASSIGN, JOIN, or SUBST command. SYS also does not work on network drives or drives redirected using INTERLNK.

Examples

To copy the MS-DOS system files and command interpreter from the disk in the current drive to a disk in drive A, type the following command:

sys a:

To copy the MS-DOS system files and command interpreter from a disk in drive B to a disk in drive A, type the following the command:

sys b: a: