MS-DOS Setup Error Message: Hard Disk Is Not Readable (96604)
The information in this article applies to:
• Microsoft MS-DOS operating system
This article was previously published under Q96604
You receive the error messages "Hard disk is not readable" and/or "Critical
disk error" when you start your computer.
The most common cause of these errors is including the device driver
ASPI4DOS.SYS in your CONFIG.SYS file. If you use this device driver, remark
it out in your CONFIG.SYS file, along with any expanded memory managers
(such as EMM386.EXE or Qemm). You can then install MS-DOS 6 (or later)
Upgrade and later restore the line(s) in your CONFIG.SYS file. This problem
commonly occurs when you have a second SCSI device (such as a CD-ROM
These errors can also occur if any of the following conditions exist:
• You have a second disk controller in your system for an external
drive or a SCSI device, such as a CD-ROM or optical disk.
To work around this problem, physically disconnect the device from
the controller and then install MS-DOS 6 (or later) Upgrade. If this
does not correct the problem, you may need to remove the controller
card from the computer and then install MS-DOS 6 or 6.2 Upgrade. After
the upgrade is successfully installed, you can reinstall the controller
card or device.
• You have a Syquest removable drive connected as a secondary hard
disk drive, and this secondary drive doesn't contain a cartridge. (Your
primary drive can be either a non-removable hard disk drive or another
To correct this problem, insert a Syquest data cartridge into the
• A sector read error occurs when reading the master boot records or
the partition boot records. Setup reads this information from the
hard disk and then writes the MBOOT?.DAT and PBOOT?.DAT files to
the Uninstall disk.
• A sector read error occurs when reading the BIOS parameter block
(BPB). Setup reads this information from the hard disk and then
writes the BPB?.DAT files to the Uninstall disk.
• A sector read error occurs when reading the root directory from the
destination hard disk. Setup reads this information from the hard
disk and then writes the ROOT.DAT file to the Uninstall disk.
• A sector read error occurs when reading the file allocation table
(FAT) from the destination hard disk. Setup reads this information
from the hard disk and then writes the ROOT.DAT file to the
• A sector read error occurs when performing the partition table
updates on the attached hard disk drives. Partition table updates
involve converting MS-DOS-compatible partitions to type 1, 4, or 6
and then converting logical sectors into 512-byte sectors in the
partition boot record.
• A sector read error occurs when reading the master boot record and
partition boot records to check for unformatted partitions.
• A sector read error occurs when reading the root directory as Setup
tries to obtain the first two root directory entries and determine
if they are MS-DOS system files (IO.SYS and MSDOS.SYS). The above
error can also occur if a sector read error occurs when moving
non-MS-DOS system file entries to make room for the MS-DOS system
files in the first two directory entries.
• Your computer is infected with the Stoned, Stoned 1, or NOINT virus.
To correct this problem, run Microsoft Anti-Virus (MSAV.EXE) from
your original MS-DOS 6.x setup disks. MSAV.EXE is located on Disk 3 of
the 3.5-inch 1.44-megabyte disk set and Disk 4 of the 5.25-inch
1.2-megabyte disk set.
• You have a second hard disk set in the CMOS settings, but you do not
have two physical hard disks.
| Modification Type:
|| Last Reviewed: