10 reasons why PCs 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.

* 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.


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 startup.
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.