Hardware Reference
In-Depth Information
Because general protection faults can be caused by software or hardware, the
first step is to restart the PC computer in Safe mode in order to narrow down the
source of the error. Restarting in Safe mode will allow you to check whether
the problem is attributable to hardware of results from a fault in a driver or an
application program.
Restarting in
Safe mode
(see page 407) allows you to test your computer in a
state in which only essential components of Windows are loaded. If you restart
your computer in Safe mode and the error message does not occur, the origin
is more likely to be a driver or program. If you restart in Safe mode and then
test your computer and the error message does occur, the issue is more likely
to be hardware or damaged Windows core files.
Safe mode starts Windows with a basic VGA video driver. To determine if
the issue you are experiencing is related to your video driver you will need to
change to the appropriate VGA driver for testing purposes. Note, however, that
if you have removed the Protected Mode drivers in order to isolate conflicts you
will have already reverted back to the basic VGA video driver.
When you start Windows in Safe mode the registry is only partially read.
Damage to the registry may not therefore be evident when running in Safe
mode and you may need to replace the existing registry data file (System.dat)
with a recent backup in order to see if this resolves the problem in which case
the cause is likely to be a damaged registry data file. The following procedure
is required in order to troubleshoot a damaged registry:
1
Boot to a DOS command prompt.
2
Remove the file attributes from the backup of the registry by typing the
following DOS command:
c:\windows\command\attrib -h -s -r c:\system.1st
3
Remove the file attributes from the current registry by typing the following
DOS command:
c:\windows\command\attrib -h -s -r c:\windows\system.dat
4
Rename the registry by typing the following command:
ren c:\windows\system.dat *.dax
5
Copy
the
backup
file
to
the
current
registry
by
typing
the
following
command:
copy c:\system.1st c:\windows\system.dat
6
Restart the computer.
Note that the System.1st file is a backup of the registry that was created
during the final stage of the
original
Windows Setup. Therefore, the 'Running
Windows for the first time' banner is displayed and Windows will finalize its
settings as if it is being installed for the first time.
If replacing the System.dat file with the System.1st file resolves the issue,
the problem may be related to a damaged Windows registry. Any programs
and device drivers that were subsequently installed may require reinstallation
to update the new registry. For this reason it is essential to keep all of your
original installation disks in a safe place!
