Workarounds for NT 4.0 Service Pack 4 Problems
with Symbios Bundled Driver (symc810.sys)
Most systems will be able to upgrade to Service Pack 4 (SP4) and operate with no problems. There are
2 conditions that can cause the system to blue screen on boot after SP4 is applied. Following the
problem descriptions is detailed information on applying the workarounds.
1) The system contains an NCRC810 device (part number 609-0391399). The Symbios driver in SP4
performs operations that can potentially trigger errata in the 810 device, resulting in a blue screen.
Most systems with this 810 device will function normally with the SP4 driver. However, on some
systems the interaction between the 810 and the PCI chipset triggers the errata and blue screen.
Systems that have been identified with this problem are some DEC Alpha systems based on Gamma
and Sable platforms and some older DELL systems with the 810 device (either on the motherboard or
a plug-in card).
Workaround: The only workaround is to replace the SP4 version of symc810.sys with the original NT
2) The system contains a Symbios host adapter based on the 810, 815, 825/825A, 860, or 875 devices.
Another vendor’s device driver (loading after the Symbios driver) snoops the PCI config space of the
Symbios device, reading past offset 0x80. This actually reads the operating registers of the 8XX
device and causes an internal data bus error in the device. The device reports this error as a SCSI
bus parity error, even though no SCSI activity is on the bus. With the SP4 bundled Symbios driver,
this erroneous parity error causes a blue screen.
Option 1: Replace the SP4 version of symc810.sys with the original NT 4.0 version.
Option 2: Obtain the latest Symbios NT driver for 810 thru 895 devices from the Symbios web site
(www.symbios.com). Copy the symc8xx.sys file to a temporary location, rename the file
symc810.sys, then copy the renamed file over the SP4 version of symc810.sys. Later versions of
the Symbios symc8xx.sys driver contain a workaround which prevents the blue screen in this
Prevention of Problem Situations #1 and #2 (using original NT 4.0 Symbios driver)
If SP4 has not yet been installed, and the user desires to insure that neither of the two problems above
will occur, it is possible to install SP4 but have the original NT 4.0 Symbios driver remain active on the
system. To do this, see Applying SP4 While Maintaining the Original NT 4.0 Symbios Driver.
Prevention of Problem Siutation #2 (using new Symbios driver)
If SP4 has not yet been installed, and the system contains an 810, 815, 825/825A, 860, or 875 device,
the potential for a blue screen due to problem #2 above can be eliminated by obtaining the latest Symbios
NT driver (symc8xx.sys) from the Symbios web site and installing it on the system. When SP4 is
subsequently installed, the new symc8xx.sys will remain in control and the SP4 Symbios driver will not
An error message will be displayed during boot that one or more drivers did not start. This message is
due to the symc810.sys SP4 driver not starting. To eliminate the error message, go to Control Panel,
Devices, find the entry “symc810.sys”. It should have a startup option of “Boot”, but not be started.
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Highlight the entry, select the Startup button, select Disabled, and click OK. This disables the
symc810.sys driver from trying to start.
Repairing an Intel Architecture(i386) System to be Bootable
(If the \winnt\system32\drivers directory can be accessed via another OS boot selection or via a bootable
MS-DOS diskette, it is much easier to replace the driver file using the methods described in Gaining
Access for Driver Update rather than going though the NT Repair process.)
If the system is based on Intel architecture (i386) and an Emergency Repair Disk for the pre-SP4
configuration is available, then the system can be made bootable at the SP4 level by running the NT 4.0
1) The repair must be done using the 3 NT 4.0 Setup Boot flex disks. It cannot be done directly by
booting from the NT 4.0 CD, because one of the setup files must be updated for the repair to work
properly. If the 3 boot disks are not available, they can be created by running either “winnt /ox” (for
16-bit OS such as MS-DOS) or “winnt32 /ox” (for Windows NT or Windows 95) from the \i386
directory on the NT 4.0 CD. The “/ox” option will create the 3 boot flex disks.
2) Once the 3 flex disks are available, the file “setupdd.sys” on disk 2 must be updated. The
“setupdd.sys” file from the original NT 4.0 installation media will not update a system file which has a
later date than that of the installation media (although it appears that it does update it during Repair).
The “setupdd.sys” file from Service Pack 2 (or higher) must be copied onto disk 2. This version
ignores the date check and will allow the user to update any system file that does not match the
installation media. This is required to allow the repair process to replace the SP4 Symbios driver
with the original NT 4.0 driver.
3) Boot the system using Disk 1 (Boot) flex disk, continuing with Disk 2 when prompted. At the first
menu, select R for Repair. For the repair process, select “Verify Windows NT system files” (unselect
the others) and Continue. At this point, any 3 party drivers (not bundled in the original NT 4.0)
required for booting must be loaded. Supply the Emergency Repair Disk when prompted.
4) When the repair process begins comparing the installation media the currently installed system files,
any file which doesn’t match will be displayed with options to skip, repair this file, or repair this and all
other non-original files. In order to complete the repair of this system in a single step, it is necessary
to select “skip” for every file except “symc810.sys”. This is tedious, but results in the system being at
SP4 with the original NT 4.0 Symbios driver with no other actions required. The “symc810.sys” file
will be displayed near the end of the compare process.
If selecting “skip” many times is not desired, repair this file and all other non-original files can be
selected. This results in the system being at either a no service pack or SP1 level (depending on the
level of the installation media). After this repair process is completed, the user must perform the
steps described in Applying SP4 While Maintaining the Original NT 4.0 Symbios Driver in order to
bring the system back to the SP4 level while keeping the original NT 4.0 Symbios driver.
5) Assuming all files except “symc810.sys” were skipped, once the compare process is completed the
system should reboot and complete the boot process properly. If it does not, insure that the updated
“setupdd.sys” file from Service Pack 2 (or above) was copied onto Disk 2 of the Setup boot flex disks.
If the older “setupdd.sys” is used, it appears that the Repair process replaced the file (it is detected
and the user is asked to skip, repair, etc.). However, even if repair is selected the newer file is not
replaced with the older file.
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Gaining Access for Driver Update
This section describes workarounds when the system is unbootable after SP4 has been installed and the
user can gain access to the \winnt\system32\drivers directory where the Symbios driver is located by a
method listed below. For all workaround options the user must be able to copy either the original NT 4.0
driver or an updated driver over the SP4 version of the driver. Once access is gained to this directory see
the section Replacing the SP4 Symbios Driver.
1) If the system is a multiboot configuration, and another boot option is bootable, boot that option to gain
access to the \winnt\system32\drivers directory. However, if the NT system files are on an NTFS
formatted partition, and the other boot option doesn’t support NTFS (such as Windows 95 or
MS-DOS), then another access option must be used.
2) If the NT system files are on a FAT partition accessible by MS-DOS, use a bootable MS-DOS diskette
to boot the system into DOS to access the \winnt\system32\drivers directory. If the NT system files
are on an NTFS formatted partition or a FAT partition not accessible from DOS, then another access
option must be used.
3) If the system is Intel-based (i386), and an Emergency Repair Disk is available, the NT Repair process
can be used to make the system bootable. This process will result in the system still being at the
SP4 level, but using the original NT 4.0 Symbios driver. See Repairing an Intel Architecture (i386)
System to be Bootable above.
4) If no Emergency Repair Disk is available for an i386 system or the system is Alpha based, then a
temporary NT 4.0 installation will need to be performed to another directory (\winnttmp suggested) to
gain access to the original \winnt\system32\drivers directory. This temporary installation can be
minimal. Be sure not to overwrite the original installation in the \winnt directory.
Replacing the SP4 Symbios Driver
The section provides detailed instructions for replacing the driver on a non-bootable system at SP4, once
access is gained to the \winnt\system32\drivers directory.
1) The first step is to select which driver to use to replace the Symbios SP4 driver. If the system uses
an NCRC810 device (part number 609-0391399), the best selection is to use the original NT 4.0
Symbios driver. This driver can be copied from the \i386 or \alpha directory on the NT 4.0 CD. If
the system doesn’t use the NCRC810 device above, the original NT 4.0 symbios driver can still be
used. However, for better storage I/O performance, the latest Symbios NT driver can be used.
Obtain this driver (for 810 thru 895 devices) from the Symbios web site (www.symbios.com) and unzip
the downloaded file (using either the –d or keep path option). The file “symc8xx.sys” is located in the
\winnt\miniport subdirectory. Copy the file to a temporary location and rename it symc810.sys.
2) Next copy the selected driver (now named “symc810.sys”) into the \winnt\system32\drivers
subdirectory, overwriting the SP4 version.
3) Shutdown (if necessary) and reboot the system into the NT SP4 installation. The system should
boot fine. If not, check (using the access method for replacing the driver) to see that the new driver
was successfully copied.
4) If a new “symc8xx.sys” driver was used, it is recommended that this driver be installed using the
normal NT 4.0 SCSI driver installation method (Control Panel, SCSI Adapters applet) with an
installation disk created from the downloaded Symbios NT driver file. This will install the driver as
“symc8xx.sys” and will insure that this driver will remain active even if SP4 is reinstalled (due to
component updates, etc.).
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Applying SP4 While Maintaining the Original NT 4.0 Symbios Driver
If the system is bootable at a pre-SP4 level (either before applying SP4 or after an NT 4.0 Repair), SP4
can be applied while maintaining the original NT 4.0 Symbios Driver. This requires either the SP4 CD or
SP4 self-extracting file and enough free disk space on the system to hold the copied or extracted SP4
Instead of executing the sefl-extracting file or the CD setup program (which will automatically apply SP4),
the SP4 files are either extracted or copied to a temporary directory on the system. Next, the SP4
version of the Symbios driver is deleted from the SP4 files. Then, the “update” program is executed
which actually installs the SP4. In this way, the original Symbios driver will be used instead of the SP4
1) Obtain the NT 4.0 SP4 CD or download the appropirate SP4 self-extracting file from the Microsoft
2) Create a temporary directory on the system. Free space of 120 MB (i386) or 150 MB (alpha) is
required (in addition to the space required by the self-extracting file, if used).
3) If using the self-extracting file, copy the file to the temporary directory and execute “FILENAME /x”
(where FILENAME is the name of the self-extracting file). This will ask the user for the directory to
extract the files to (current directory is the default) and then extracts all of the files. It does NOT
install SP4 at this time.
If using the SP4 CD, the user has a choice. On some versions of the CD, the self-extracting files are
located in the root directory. If desired, the appropriate self-extracting file can be used as described
above. Otherwise, go to the appropiate platform directory (\i386 or \alpha) and XCOPY /S this
directory to the temporary directory on the system. Using xcopy with the /s parameter will maintain
the subdirectory structure from the CD.
4) Delete the SP4 version of the Symbios driver by executing “del symc810.*” from the temporary
directory (or deleting the file from Windows Explorer). Use symc810.* in case the driver file is in
compressed format (symc810.sy_).
5) From the temporary directory, “cd update”, then execute “update”. This will install SP4 from the
temporary directory files. A dialog box will display when the update program attempts to copy the
SP4 symc810.sys file. Select the Skip file button. Another dialog box displays with a warning.
Select OK. The SP4 installation will complete and the system will reboot. At this point, SP4 will be
installed but the original NT 4.0 Symbios driver will be active.
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