Troubleshooting

ave many possible causes. Troubleshooting is used in many fields such asengineering, system administration, electronics, automotive repair, anddiagnostic medicine.Troubleshooting requiresidentification of themalfunction(s) or symptoms within a system. Then, experience is commonly used to generate possible causes of the symptoms. Determining which cause is most likely is often a process of elimination - eliminating potential causes of a problem. Finally, troubleshooting requiresconfirmation that the solution restores the product orprocess to its working state.
In general, troubleshooting is the identification of, ordiagnosis of "trouble" in a [system] caused by a failureof some kind. The problem is initially described as symptoms of malfunction, and troubleshooting is the process of determining the causes of these symptoms.

A system can be described in terms of its expected, desired or intended behavior (usually, for artificial systems, its purpose). Events or inputs to the system are expected to generate specific results or outputs. (For example selecting the "print" option from various computer applications is intended to result in a hardcopy emerging from some specific device). Any unexpected or undesirable behavior is a symptom. Troubleshooting is the process of isolating the specific cause or causes of the symptom.Frequently the symptom is a failure of the product or process to produce any results. (Nothing was printed, for example).

The methods of forensic engineering are especially useful in tracing problems in products or processes, and a wide range of analytical techniques are available to determine the cause or causes of specific failures. Corrective action can then be taken to prevent further failures of a similar kind. Preventative action is possible using FMEAand FTA before full scale production, and these methods can also be used for failure analysis.

Responding to and Recovering from a Virus

Does your computer system seem to run slower than it should? Does it crash often and display error messagesyou don't recognize? Playmusical tunes you've never heard before? If your computer acts like it's inhabited by ghosts, you may have a computer virus or some kind of spyware.

On the other hand, anunhealthy or overloaded system could cause some of these same problems — particularly sluggish performance. Your hard drive could just be running out of space, or you could haveinsufficient memory resources for the applications you're running.

So how do you tell the difference between a virus and a system problem? Generally speaking, if you notice sudden, unexpected behavior, like strange sounds coming from your computer or file names you don't recognize, you probably have a virus.

If you think you've contracted a computer virus, you have several options:

• Run antivirus software
• Replace files
• Run a disk-repair utility
• Reformat your drive

5 ways to speed up your PC

By following a few simple guidelines, you can maintain your computer and keep it running smoothly. 1. Free up disk space By freeing disk space, you can improve the performance of your computer. The Disk Cleanup tool helps you free up space on your hard disk. The utility identifies files that you can safely delete, and then enables you to choose whether you want to delete some or all of the identified files. 2. Speed up access to data Disk fragmentation slows the overall performance of your system. When files are fragmented, the computer must search the hard disk when the file is opened to piece it back together. The response time can be significantly longer. 3. Detect and repair disk errors In addition to running Disk Cleanup and Disk Defragmenter to optimize the performance of your computer, you can check the integrity of the files stored on your hard disk by running the Error Checking utility. 4. Protect your computer against spyware Spyware collects personal information without letting you know and without asking for permission. From the Web sites you visit to usernames and passwords, spyware can put you and your confidential information at risk. In addition to privacy concerns, spyware can hamper your computer's performance. 5. Learn all about ReadyBoost If you're using Windows Vista, you can use ReadyBoost to speed up your system. A new concept in adding memory to a system, it allows you to use non-volatile flash memory—like a USB flash drive or a memory card—to improve performance without having to add additional memory.

Why Do I Need to Backup My Files?

Don't fall into the old paradigm of "it will never happen to me." While there is certainly a chance that you will never have a need for the backups you make of yourfiles, if something does happen to your computer you will certainly be glad that you have them. And you do not have to backup your entire computer, although this is certainly something that many people do, but only the files that are of the mostimportance to you.

Some things are easily replaced, and there is no need to backup these sorts of things, but those irreplaceable documents or files that are yours and yours alone should be saved in a place where they cannot be damaged. That way, no matter what happens to your computer, you can have security in the fact that all of your files are available inbackup.

How do I protect my computer?

There are several things that you should do toprotect your computer from virusinfections:

• Use a high-quality anti-virus program,and be sure to update it regularly. Use it to scan any files, programs, software, or diskettes (even new software from a commercial company) before you use them on your computer.
• Make back-up copies of important documents or files and store them on separate diskettes. Making backups will also protect your information against accidental file deletion, diskette failure, and other damage.
• Whenever you use a computer in a campus lab, be sure to reboot or run "cleanup" before you start your session and log out when you end your session.
• Do not share commerical software with anyone. It is a violation of the author's copyright to distribute such material, and it is a way to spread viruses.
• When you get public domain (PD) software for which the author has granted permission to make copies, get it from a reliable source. (For example, and individual you do not know is not a reliable source.) Before you run PD material, use an anit-virus program to inspect for known viruses.
• Always scan your disks and files after using them on another computer.
• Always scan all files you download from the Internet.
• Always scan Word or Excel file email attachments before you read them.

The World's Worst Viruses

Some viruses and worms won'tdestroy your data, while others dotremendous damage. For example, the LoveLetter virus overwrote files and inserted viral code on hard drives around the globe two years ago. "As far as what [virus writers] can do, the sky is the limit," says April Goostree, virus manager forMcAfee.com. "In the antivirus industry, we never say 'never' anymore. Because as soon as you do, you are going to be proven wrong. It's anybody's guess about what the next virus will do." Here's a look at ten of the most malignant viruses and worms of all time. 10. Surreptitious Sircam 9. Red Raider 8. Bad Benjamin 7. Numbing Nimda 6. Tennis Anyone? 5. (Expletive Deleted) Explorer 4. Maniacal Magistr 3. Malevolent Melissa 2. Klez the Conquerer 1. Love Hurts

History of Computer Viruses

The first computer virus to openly make it to the public was a program called "Elk Cloner". It was created by Rich Skrenta, a computer programmer who was in high school when this virs was created in 1982. Elk Cloner attached itself to the Apple DOS 3.3 operating system and was later spreaded by a floppy disk.When the virus was created, it was intentionally made as a joke by the high school student, who inputted the virus into a game in which the virus was set off after the 50th time of using the game. When the virus was set off, ablank screen appeared and displayed a poem about the virus. The computer then becameinfected. The first PC virus was a boot sector virus named (c)Brain.Two brothers, Basit and Amjad Farooq Alvi, whose only intentions were to protect their work from piracy and to target copyright infringers, programmed it. However, according to analysts, the Ashar virus, which was a variant of Brain, possibly was created before the (c)Brain. Before network computer expansion, most viruses were spreaded through removable media, such as floppy disks. These viruses infected programs stored in the disks, while others were inputted into the disk boot sectors, and activated when the user booted the computer from the disk. The traditional and typical virus characteristics common to us now emerged in the 1980s, where there was an increase of BBS (Bulletin Board System, where a computer system runs software that allows users to dial into the system over a phone line), modem use, and software sharing. BBScontributed greatly to the rapid spread of Trojan horses, and viruses were orginally written to target popular software traders. Traders who were in a hurry to retrieve the lastest software were usually the easiest prey to infect viruses with. In the mid 1990s, macro viruses came into the scene and became common quickly. Ironically, some versions of Microsoft Word allowed the macro virus to multiply and gain additional blank lines. This can cause a misleading detection, as others would see the new strands of the macro virus as a new virus. Viruses then began spreading via instant messaging. Typically, it sends a web address to everybody in the contact list, and anyone who so much as click on the link would be prone of an immediate infection. However, there are thousands and thousands of viruses operating online and new viruses are discovered every single day.