Err Msg: "No Room for System on Destination Disk" with SYS (57730)
The information in this article applies to:
• Microsoft MS-DOS operating system 3.1
• Microsoft MS-DOS operating system 3.2
• Microsoft MS-DOS operating system 3.21
• Microsoft MS-DOS operating system 3.3
• Microsoft MS-DOS operating system 3.3a
• Microsoft MS-DOS operating system 4.0
• Microsoft MS-DOS operating system 4.01
• Microsoft MS-DOS operating system 5.0
• Microsoft MS-DOS operating system 5.0a
• Microsoft MS-DOS operating system 6.0
• Microsoft MS-DOS operating system 6.2
• Microsoft MS-DOS operating system 6.21
• Microsoft MS-DOS operating system 6.22
This article was previously published under Q57730
In the Microsoft MS-DOS user's manuals, the SYS command entry states that
you do not need to reformat your disk when you upgrade to a later version
of MS-DOS. SYS updates system disks even though the new system files are
larger and must be broken up to fit in the available disk space.
However, when upgrading some system disks, SYS returns the following error
No room for system on destination disk
This error message is caused by one of the following:
• There is not enough free space anywhere on the destination disk for
the relocatable part of the system files.
Delete some files to make room for the system files. This
is documented in Appendix F of the "Microsoft MS-DOS User's
Guide and Reference" for versions 4.01 and earlier, under the "No room
for system on destination disk" error message.
• A file occupies the first clusters of the disk on a non-system
If a disk utility is available to find which file(s) occupy the
first clusters of the disk, erase or move those files to clear
the space needed for the system.
If you have the MS-DOS 5, 6, or 6.2 Upgrade, you can run Setup
with the /M parameter.
If the previous two options are not available, you must reformat the
• The disk has an original equipment manufacturer (OEM) version of
MS-DOS that does not use the Microsoft naming convention for the
hidden system files.
Contact the OEM supplier for an MS-DOS upgrade. You should continue
running the OEM version of MS-DOS. However, if you must change to
the Microsoft MS-DOS packaged product, see the information provided
• Cluster 2 is a lost cluster and cannot be used to hold IO.SYS.
Run MS-DOS CHKDSK /F to correct the lost allocation unit.
If you are using MS-DOS 6.2 or later, run SCANDISK.
There is a quick solution for the OEM MS-DOS problem mentioned above.
This solution requires that you have a good understanding of MS-DOS,
and that you have a third-party utility to remove the Hidden, System,
and Read-Only attributes from the system files.
The MS-DOS SYS command looks for the files named IO.SYS and MSDOS.SYS
on the destination disk. If these files are not found, because they do
not exist or are named differently, SYS assumes the disk is not a
system disk and attempts to install the new system files starting at
cluster 2 (IO.SYS must be contiguous starting at cluster 2).
Some OEMs, such as IBM, use different names for the system files. To
make SYS work with these disks, you can rename the two files to IO.SYS
and MSDOS.SYS, as in the following example. (The following example
uses IBM PC-DOS naming conventions.)
• Using a third-party attribute change utility, remove the Hidden,
Read-Only, and System attributes from IBMBIO.COM and IBMDOS.COM.
MS-DOS does not provide a utility to set or reset the Hidden and
System attributes of a file, because you should not tamper with
• Rename these two files as follows:
ren ibmbio.com io.sys
ren ibmdos.com msdos.sys
• Use the attribute utility to replace the Hidden, Read-Only, and
The SYS command should work correctly after you make the above changes.
The SYS command does not transfer COMMAND.COM to the destination floppy
disk in MS-DOS versions 3.3x through 4.x, so you must do that manually.
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