Fatal
error: the system has become unstable or is busy," it says. "Enter to
return to Windows or press Control-Alt-Delete to restart your computer. If you
do this you will lose any unsaved information in all open applications."
You have
just been struck by the Blue Screen of Death. Anyone who uses Mcft Windows will
be familiar with this. What can you do? More importantly, how can you prevent
it happening?
1 Hardware conflict
The
number one reason why Windows crashes is hardware conflict. Each hardware
device communicates to other devices through an interrupt request channel
(IRQ). These are supposed to be unique for each device.
For
example, a printer usually connects internally on IRQ 7. The keyboard usually
uses IRQ 1 and the floppy disk drive IRQ 6. Each device will try to hog a
single IRQ for itself.
If there are a lot of
devices, or if they are not installed properly, two of them may end up sharing
the same
IRQ
number. When the user tries to use both devices at the same time, a crash can
happen. The way to check if your computer has a hardware conflict is through
the following route:
* Start-Settings-Control
Panel-System-Device Manager.
Often if a device has a problem a yellow '!'
appears next to its description in the Device Manager. Highlight Computer (in
the Device Manager) and press Properties to see the IRQ numbers used by your
computer. If the IRQ number appears twice, two devices may be using it.
Sometimes
a device might share an IRQ with something described as 'IRQ holder for PCI
steering'. This can be ignored. The best way to fix this problem is to remove
the problem device and reinstall it.
Sometimes
you may have to find more recent drivers on the internet to make the device
function properly. A good resource is www.driverguide.com. If the device is a
soundcard, or a modem, it can often be fixed by moving it to a different slot
on the motherboard (be careful about opening your computer, as you may void the
warranty).
When
working inside a computer you should switch it off, unplug the mains lead and
touch an unpainted metal surface to discharge any static electricity.
To be
fair to Mcft, the problem with IRQ numbers is not of its making. It is a legacy
problem going back to the first PC designs using the IBM 8086 chip. Initially
there were only eight IRQs. Today there are 16 IRQs in a PC. It is easy to run
out of them. There are plans to increase the number of IRQs in future designs.
2 Bad Ram
Ram (random-access memory) problems might bring on the blue screen of
death with a message saying Fatal Exception Error. A fatal error indicates a
serious hardware problem. Sometimes it may mean a part is damaged and will need
replacing.
But a fatal error caused by
Ram might be caused by a mismatch of chips. For example, mixing 70-nanosecond
(70ns)
Ram with 60ns Ram will usually force the computer to run all the Ram at the
slower speed. This will often crash the machine if the Ram is overworked.
One way
around this problem is to enter the BIOS settings and increase the wait state
of the Ram. This can make it more stable. Another way to troubleshoot a
suspected Ram problem is to rearrange the Ram chips on the motherboard, or take
some of them out. Then try to repeat the circumstances that caused the crash.
When handling Ram try not to touch the gold connections, as they can be easily
damaged.
Parity
error messages also refer to Ram. Modern Ram chips are either parity (ECC) or
non parity (non-ECC). It is best not to mix the two types, as this can be a
cause of trouble.
EMM386
error messages refer to memory problems but may not be connected to bad Ram.
This may be due to free memory problems often linked to old Dos-based
programmes.
3 BIOS settings
Every
motherboard is supplied with a range of chipset settings that are decided in
the factory. A common way to access these settings is to press the F2 or delete
button during the first few seconds of a boot-up.
Once
inside the BIOS, great care should be taken. It is a good idea to write down on
a piece of paper all the settings that appear on the screen. That way, if you
change something and the computer becomes more unstable, you will know what
settings to revert to.
A common BIOS error concerns the CAS latency.
This refers to the Ram. Older EDO (extended data out) Ram has a CAS latency of
3. Newer SDRam has a CAS latency of 2. Setting the wrong figure can cause the
Ram to lock up and freeze the computer's display.
Mcft Windows is better at allocating IRQ numbers than any BIOS. If
possible set the IRQ numbers to Auto in the BIOS. This will allow Windows to
allocate the IRQ numbers (make sure the BIOS setting for Plug and Play OS is
switched to 'yes' to allow Windows to do this.).
4 Hard disk drives
After a
few weeks, the information on a hard disk drive starts to become piecemeal or
fragmented. It is a good idea to defragment the hard disk every week or so, to
prevent the disk from causing a screen freeze. Go to
*
Start-Programs-Accessories-System Tools-Disk Defragmenter
This will start the procedure. You will be unable to write data to the
hard drive (to save it) while the disk is defragmenting, so it is a good idea
to schedule the procedure for a period of inactivity using the Task Scheduler.
The Task
Scheduler should be one of the small icons on the bottom right of the Windows
opening page (the desktop).
Some
lockups and screen freezes caused by hard disk problems can be solved by
reducing the read-ahead optimisation. This can be adjusted by going to
* Start-Settings-Control
Panel-System Icon-Performance-File System-Hard Disk.
Hard
disks will slow down and crash if they are too full. Do some housekeeping on
your hard drive every few months and free some space on it. Open the Windows
folder on the C drive and find the Temporary Internet Files folder. Deleting
the contents (not the folder) can free a lot of space.
Empty
the Recycle Bin every week to free more space. Hard disk drives should be
scanned every week for errors or bad sectors. Go to
* Start-Programs-Accessories-System
Tools-ScanDisk
Otherwise assign the Task
Scheduler to perform this operation at night when the computer is not in use.
5 Fatal OE exceptions and
VXD errors
Fatal OE exception errors
and VXD errors are often caused by video card problems.
These can often be resolved
easily by reducing the resolution of the video display. Go to
* Start-Settings-Control
Panel-Display-Settings
Here you
should slide the screen area bar to the left. Take a look at the colour
settings on the left of that window. For most desktops, high colour 16-bit
depth is adequate.
If the
screen freezes or you experience system lockups it might be due to the video
card. Make sure it does not have a hardware conflict. Go to
* Start-Settings-Control
Panel-System-Device Manager
Here, select the + beside Display Adapter. A line of text describing
your video card should appear. Select it (make it blue) and press properties.
Then select Resources and select each line in the window. Look for a message
that says No Conflicts.
If you
have video card hardware conflict, you will see it here. Be careful at this
point and make a note of everything you do in case you make things worse.
The way
to resolve a hardware conflict is to uncheck the Use Automatic Settings box and
hit the Change Settings button. You are searching for a setting that will
display a No Conflicts message.
Another useful way to
resolve video problems is to go to
* Start-Settings-Control
Panel-System-Performance-Graphics
Here you should move the Hardware Acceleration
slider to the left. As ever, the most common cause of problems relating to
graphics cards is old or faulty drivers (a driver is a small piece of software
used by a computer to communicate with a device).
Look up your video card's
manufacturer on the internet and search for the most recent drivers for it.
6 Viruses
Often
the first sign of a virus infection is instability. Some viruses erase the boot
sector of a hard drive, making it impossible to start. This is why it is a good
idea to create a Windows start-up disk. Go to
* Start-Settings-Control
Panel-Add/Remove Programs
Here, look for the Start Up
Disk tab. Virus protection requires constant vigilance.
A virus
scanner requires a list of virus signatures in order to be able to identify
viruses. These signatures are stored in a DAT file. DAT files should be updated
weekly from the website of your antivirus software
An
excellent antivirus programme is McAfee VirusScan by Network Associates (
www.nai.com). Another is Norton AntiVirus 2000, made by Symantec (
www.symantec.com).
7 Printers
The action of sending a
document to print creates a bigger file, often called a postscript file.
Printers
have only a small amount of memory, called a buffer. This can be easily overloaded.
Printing a document also uses a considerable amount of CPU power. This will
also slow down the computer's performance.
If the
printer is trying to print unusual characters, these might not be recognised,
and can crash the computer. Sometimes printers will not recover from a crash
because of confusion in the buffer. A good way to clear the buffer is to unplug
the printer for ten seconds. Booting up from a powerless state, also called a
cold boot, will restore the printer's default settings and you may be able to
carry on.
8 Software
A common
cause of computer crash is faulty or badly-installed software. Often the
problem can be cured by uninstalling the software and then reinstalling it. Use
Norton Uninstall or Uninstall Shield to remove an application from your system
properly. This will also remove references to the programme in the System
Registry and leaves the way clear for a completely fresh copy.
The System Registry can be corrupted by old references to obsolete
software that you thought was uninstalled. Use Reg Cleaner by Jouni Vuorio to
clean up the System Registry and remove obsolete entries. It works on
Windows 95, Windows 98,
Windows 98 SE (Second Edition), Windows Millennium Edition (ME), NT4 and
Windows 2000.
Read the
instructions and use it carefully so you don't do permanent damage to the
Registry. If the Registry is damaged you will have to reinstall your operating
system. Reg Cleaner can be obtained from www.jv16.org
Often a
Windows problem can be resolved by entering Safe Mode. This can be done during
start-up. When you see the message "Starting Windows" press F4. This
should take you into Safe Mode.
Safe
Mode loads a minimum of drivers. It allows you to find and fix problems that
prevent Windows from loading properly.
Sometimes installing Windows is difficult because of unsuitable BIOS
settings. If you keep getting SUWIN error messages (Windows setup) during the
Windows installation, then try entering the BIOS and disabling the CPU internal
cache. Try to disable the Level 2 (L2) cache if that doesn't work.
Remember to restore all the
BIOS settings back to their former settings following installation.
9 Overheating
Central
processing units (CPUs) are usually equipped with fans to keep them cool. If
the fan fails or if the CPU gets old it may start to overheat and generate a
particular kind of error called a kernel error. This is a common problem in
chips that have been overclocked to operate at higher speeds than they are
supposed to.
One
remedy is to get a bigger better fan and install it on top of the CPU.
Specialist cooling fans/heatsinks are available from www.computernerd.com or
www.coolit.com
CPU
problems can often be fixed by disabling the CPU internal cache in the BIOS.
This will make the machine run more slowly, but it should also be more stable.
With all
the new construction going on around the country the steady supply of
electricity has become disrupted. A power surge or spike can crash a computer
as easily as a power cut.
If this
has become a nuisance for you then consider buying a uninterrupted power supply
(UPS). This will give you a clean power supply when there is electricity, and
it will give you a few minutes to perform a controlled shutdown in case of a
power cut.
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