5 Reasons Why PC
Crash:
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.
