when you work on your computer it is possible to harm the computer and yourself. The most common accident which happens while attempting to fix a computer problem is erasing software and data. unless you know what you are doing, you can cause damage. To prevent these sorts of accidents, and also the physically dangerous ones, you only need to take a few safety precautions. The text below will describe the potential sources of damage to computers and how to protect your computer and yourself against them.

Power to the Computer

To protect yourself and the computer components while working inside a computer, turn the power off, unplug the computer, and always ground yourself to discharge any static electricity built up in your body, either by wearing an anti static wrist band or by touching any unpainted part of the computer case.

Think of the monitor and the power supply unit (PSU) as "black boxes". Never remove the covers unless you know about the hazards of charged capacitors. The power supply unit and the monitor can hold dangerous levels of electricity even after they are turned off and disconnected from the power source.

Protecting Against ESD

Protecting the computer against electrostatic discharge (ESD), more commonly known as static electricity, always ground yourself before touching any of the electronic components, including the hard drive, motherboard, expansion cards, processors and memory modules. there are a number of ways you can ground yourself and the computer components by using one of the methods below.

Ground bracelet or anti static wrist strap: A ground bracelet is a strap you wear around your wrist. the other end is attached to a grounded conductor such as the computer case or a ground mat or it can be plugged into a wall outlet (Note: only the ground prong makes a connection!). The bracelet also contains a current-limiting resistor which prevents electricity from harming you.

Ground Mats: Ground mats usually come equipped with a cord to plug into a wall outlet to provide a grounded surface to work on. Remember if you lift the component off the mat, it is no longer grounded and susceptible to ESD.

Static Shielding Bags: All new components are supplied in static shielded bags. It is a good idea to save these bags to store spare computer components in to keep them protected from ESD.

The best solution for protecting against ESD is to use a ground bracelet together with a ground mat. You should consider a ground bracelet to be essential equipment while working on a computer. if you find yourself in a situation when your without one, touch the computer case before you touch any components. Leave components inside their protective bags until they are ready to be used. Work on hard floors, not carpet, because walking on and shuffling your feet on carpet generates static electricity. Generally, don't work on a computer if you or the computer have just come inside from the cold.

When handling motherboards and expansion cards, don't touch the chips on the boards. don't stack the boards on top of each other, which could accidentally dislodge a chip. hold cards by the edges, but be careful not to touch the connections of the cards.

Don't touch the chips with a magnetized screwdriver. when using a multimeter to measure electricity, be careful not to touch a chip with the probes. when changing DIP switches, don't use a graphite pencil, because graphite conducts electricity; a small screwdriver works the best. Do not store expansion cards within one foot of the monitor, because the monitor can discharge as much as 29,000 volts of ESD onto the screen.

Protecting Hard Drives and Disks

Always turn the computer off before moving it, to protect the hard drive, which is always spinning while the computer is turned on (unless the drive has a sleep mode). Never jar a computer while the hard disk is running. Avoid placing a PC on the floor, where the user can accidentally kick it.

Follow the user precautions to protect disks. keep them away from magnetic fields, heat and extreme cold. Treat disks with care and they will last for years.

Google is clearly the mot popular general-purpose search engine on the Internet today

But most people don't use it to its best advantage. Do you just type in a keyword or two and hope for the best? This may be the quickest and simplest way to search, but with more than 3 billion pages in Google's index, there's an easier way to get the results to a manageable number.

Google is a powerful tool which eases and enhances your Internet exploring. Google's search options go beyond simple keywords, the Web, and even its own programmers. Let's look at some of Google's lesser-known options.

Syntax Search Tricks

Using a special syntax is a way to tell Google that you want to restrict your searches to certain elements or characteristics of Web pages. Google has a fairly complete list of its syntax elements at

www.google.com/help/operators.html

Here are some advanced operators that can help narrow down your search results.

Intitle: placed at the beginning of a query word or phrase (intitle:"Google search") restricts your search results to just the titles of the Web pages.

Intext: does the opposite of intitle:, searching only the body text, ignoring titles, links, and so forth. Intext: is perfect when what you're searching for might commonly appear in URLs. If you're looking for the term HTML, for example, and you don't want to get results such as

www.mysite.com/index.html

you can enter intext:html.

Link: lets you see which pages are linking to your Web page or to another page you're interested in. For example, try typing in

link:http://www.pcmag.com

Try using site: (which restricts results to top-level domains) with intitle: to find certain types of pages. For example, get scholarly pages about your favourite author by searching for intitle:"favourite author"site:edu.

Experiment with mixing various elements; you'll develop several strategies for finding the stuff you want more effectively.

The site: command is very helpful as an alternative to the mediocre search engines built into many sites.

Google has a number of services that can help you accomplish tasks you may never have thought to use Google for. For example, the new calculator feature

(www.google.com/help/features.html#calculator)

lets you do both math and a variety of conversions from the search box.

Google can help you find out if you've got the right spelling—and the right word—for your search. Enter a misspelled word or phrase into the query box (try "gougle serch") and Google may suggest a proper spelling. This doesn't always work; it works best when the word you're searching for can be found in a dictionary. Once you search for a properly spelled word, look at the results page, which repeats your query. (If you're searching for "Google search," underneath the search window will appear a statement such as Searched the web for "Google search.") You'll discover that you can click on each word in your search phrase and get a definition from a dictionary.

Lets say you want to contact someone and don't have the phone number handy. Google can help you with that, too. Just enter a name, city, and state. (The city is optional, but you must enter a state.) If a phone number matches the listing, you'll see it at the top of the search results along with a map link to the address.

Extended Googling

Google offers several services that give you a head start in focusing your search. Google Groups

(http://groups.google.com)

indexes literally millions of messages from decades of discussion on Usenet. Google even helps you with your shopping via two tools: Froogle
(http://froogle.google.com),

which indexes products from online stores, and Google Catalogs
(http://catalogs.google.com),

which features products from more 6,000 paper catalogs in a searchable index. And this only scratches the surface. You can get a complete list of Google's tools and services at

(www.google.com/options/index.html)

You've probably already gotten used to using Google in your browser. But have you ever thought of using Google outside of your browser?

Google Alert

(www.googlealert.com)

Google alert monitors your search terms and e-mails you information about new additions to Google's Web index. (Google Alert is not affiliated with Google; it uses Google's Web services API to perform its searches.) If you're more interested in news stories than general Web content, check out the beta version of Google News Alerts

(www.google.com/newsalerts)

This service (which is affiliated with Google) will monitor up to 50 news queries per e-mail address and send you information about news stories that match your query. (Hint: Use the intitle: and source: syntax elements with Google News to limit the number of alerts you get.)

Google on the telephone? This service is brought to you by Google Labs

(http://labs.google.com),

a place for experimental Google ideas and features (which may come and go, so what's there at this writing might not be there when you decide to check it out). With Google Voice Search you dial the Voice Search phone number, speak your keywords, and then click on the indicated link. Every time you say a new search term, the results page will refresh with your new query (you must have JavaScript enabled for this to work). Remember, this service is still in an experimental phase, so don't expect 100 percent success.

In 2002, Google released the Google API (application programming interface), this is a way for programmers to access Google's search engine results without violating the Google Terms of Service. A lot of people have created useful applications not available from Google itself, such as Google Alert. For many applications, you'll need an API key, which is available free from
(www.google.com/apis)

Thanks to the many different search properties, Google goes far beyond a regular search engine. Give the tricks in this article a try and You'll be amazed at how many different ways Google can improve your Internet searching.

Description

After installing Virus-Scan software, you may wonder, how do I know if it's working? The answer is a test virus. The EICAR Standard Anti-Virus Test File is a combined effort by anti-virus vendors throughout the world to implement one standard by which customers can verify their anti-virus installations.


Solution

To test your anti-virus installation, copy the following line without brackets and quotes " into its own file (notepad,text document), then save the file with the name EICAR.COM. More detailed instructions are found below.

("X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*")

The file size will be 68 or 70 bytes.

If the Virus Scan is running and configured correctly, when you try to save the file, Virus Scan will detect the virus. If the Virus Scan is not running, start it and scan the directory that contains EICAR.COM, or right click on the file and select scan with your anti-virus program, When your software scans this file, it will report finding the EICAR test file.

Note that this file is NOT A VIRUS. Delete the file when you have finished testing your installation to avoid alarming other users.

The eicar test virus is available for download from the following web site:
http://www.eicar.org/download/eicar.com
How to create an Eicar.com file

1. Click on Start.
2. Select Run.
3. In the Open box type: notepad
4. Maximize the window.
5. Highlight the following line of text without the quotes and brackets (" ")

("X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*")

6. Right click on the highlighted text and choose 'copy'.
7. Switch back to Notepad.
8. Right click anywhere inside of Notepad and select 'paste'.
9. Click the File menu and select 'save as'.
10. Change the 'Save as Type' to 'all files'.
11. Name the file eicar.com.

NOTE : Not connecting the power cables correctly can damage the drive. Normally, the
power connector can only fit one way.

Connecting the Interface Connector

Connect the 40-pin IDE cable to the back of the Drive, making sure the coloured (red) stripe on
the IDE cable is connected to pin 1 on the drive. Pin 1 is closest to the Power Connector.

NOTE : normally, the IDE connector is keyed
and will only fit one way.


Connecting the Sound Card

If the computer is using a sound card, the drive is connected to the sound card with an audio
cable. The supplied analog audio cable fits most sound cards or one can be purchased at a local
computer store.
Refer to the manual for the sound card
for detailed information regarding this
connection.

Replacing the Computer Cover

When the installation of the drive unit is
complete, replace the computer cover.

Device Drivers

When using Windows 2000 Pro/XP or Window NT Workstation Ver. 4.0, no special device driver is required. Your system will find and install the drivers, upon Power On and bootup after installing and connecting the new drive, will recognize and load software drivers automatically.
The DOS and Windows 3.1 users can download the DOS Device drivers via the Internet.

For Windows 2000 Pro/XP Users

.■ In order to ensure normal drive operation, please check the following:

• The drive is displayed in

Windows 2000 Pro/XP : [Control Panel]-[System]-[Hardware]-[Device Manager]-
[DVD/CD-ROM-Drive]

• 32-bit is displayed in [Control Panel]-[System]-[Performance]

■ If the drive is not recognized by your computer, please check the following items.

• If an indicator is displayed on the IDE controller in [Control Panel]-[System]-[Device
Manager]-[Hard Disk Controller], you will need to contact your PC’s manufacturer or the
motherboard’s manufacturer and get the appropriate IDE controller driver.

■ Run Add New Hardware in Control Panel to let PC search again for new device.
For Windows NT Workstation Ver.4.0 Users

■ In order to ensure normal drive operation, please check to see if the drive is displayed on
the IDE controller in [Control Panel]-[SCSI Adapter]-[Device]

■ If the drive is not recognized by your computer, an indicator is displayed on the IDE
controller in [Control Panel]-[SCSI Adapter]-[Devices], you will need to contact your PC’s
manufacturer or the motherboard’s manufacturer and get the appropriate IDE controller driver.

How to Use Disks

When using CD-ROM discs or DVD discs, don’t put any stickers or labels to the discs. Using
discs with them attached will cause read and write errors and also damage the disc.
The Discs in DVD/CD drives rotate at a very high
speed! DO NOT use damaged, cracked or
warped discs. The drive’s optical unit may be
damaged if they break.

Emergency Eject

Most DVD/CD drives have a feature that allows the CD to be ejected manually if necessary such as failure of the drive or a power outage.
NOTE: Don’t use this feature except in an emergency.

1) Turn the power to OFF.

2) Poke a fine-tipped object (such as a straightened heavy duty paper clip) into the small hole
above the eject button. The front door will pop open and the disk tray will come partway out.

3) Pull the front door to open it all the way, then grip the disc tray between thumb and forefinger and pull it straight out.
NOTE: This feature is a last measure to
be used only in an emergency.
Using it excessively will cause the drive to malfunction.

Troubleshooting a DVD/CD Drive

• The drive doesn’t have power.
• Is the power supply cable from the host computer plugged in?
• Is the Power Connector to the drive securely attached?
• The system doesn’t start.
• Are the Primary and Secondary connections and the Master and Slave settings correct?
• Is the total length of the IDE cable 18 inches or less?
• Is each connector completely attached?
Movement of the PC may loosen connections.
• Cannot Read or Write Discs.
• Is the condition of everything else in the system (CPU, hard disc, and others)
as it should be?
• Does the CD, DVD disc have dirt or scratches?
• Did a screen saver or other application operate while writing to the disc?
• Is there enough free space on the CD, DVD disc?
• Does writing fail even using the simulation test?
• Is the disc loaded in the drive with the read/write surface facing the right direction?
(label up)
• Is the drive installed in the correct orientation?
• Was the drive or disc moved from a low temperature environment to a high temperature
environment? (There is a possibility of condensation on the lens in the drive or on the
surface of the disc.)

10 reasons why PCs crash, you must Know

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 hit by the Blue Screen of Death. Anyone who uses Microsoft Windows will be familiar with this. What can you do? More importantly, how can you prevent it from 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 meant 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 use a single IRQ for itself.

If you have a lot of devices connected to your computer, or if they are not installed properly, two of them can end up sharing the same IRQ number. When the user tries to use both devices at the same time, a crash can happen. To check if your computer has a hardware conflict is through the device manager:

* Start/Settings/Control Panel/System/Device Manager.

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 no numbers appear select the "view" tab then "resources by type" and then interrupt request (IRQ). If the IRQ number appears twice, two devices may be using it.

Often a device might share an IRQ with something described as 'IRQ holder for PCI steering'. This can be ignored. The easiest way to fix this problem is to uninstall the problem device and then reinstall it.

If the device is a sound card, or a modem, it can usually 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 make sure its switched off, unplug the mains lead and touch an unpainted metal surface to discharge any static electricity in your body.

To be fair to Microsoft, the problem with IRQ numbers is not their fault. 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 the 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 programs.

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, 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 SD Ram has a CAS latency of 2. Setting the wrong figure can cause the Ram to lock up and freeze the computer's display.

Microsoft 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 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 desktop on the task bar.

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/Scan Disk

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

Select the + beside Display Adapter. A line of text describing your video card should appear. Highlight it 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. 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 its a good idea to create a Windows start-up disk. Go to

* Start/Settings/Control Panel/Add/Remove Programs

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 web site of your anti-virus software manufacturer.

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 should 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.

The System Registry can be corrupted by old references to obsolete software that you thought was uninstalled. There are plenty of free registry cleaners available Regscrub XP and easycleaner are two good one's.

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 over clocked 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.

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

A power surge or spike can crash a computer and damage the CPU and motherboard 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.