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 manufacturer.
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.
10. Power supply problems
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.
It is a good investment if your data are critical,
because a power cut will cause any unsaved data to be lost.
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