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Saturday, July 28, 2018



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Computer handling is sometimes called computer maintenance. Computer handling is the process of caring the computer and its accessories so that it can perform its work properly.
This is the process of dealing with power disturbances.
Power disturbances include:
  • surge: is the voltage increase above 110% of the normal voltage
  • brown out: this is power sags which last just less than a second. it is caused by power overload
  • sparks: this is power overload which last for fractions of a second. It is caused by starting and stopping of heavy welding and lightening equipment.
  • liquid: liquid causes short circuits
  • dust: tends to block the flow of electric signals in a computer system
  • heat : chips in the a computer system cannot pass high voltage at very low temperature nor high temperature.
  • magnetism : can delete all information in magnetic disk
The importance of using UPS, Surge protectors and Voltage Stabilizers
Explain the importance of using UPS, Surge protectors and Voltage Stabilizers
UPS an uninterruptible power supply is a device which immediately provides backup power during power failure. A UPS is normally used for computers or other devices such as networking equipments. This will allow the users to save everything to avoid data loss and properly shut the computer down.
surge protector (or surge suppressor or surge diverter) is an appliance or device designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or shorting to ground any unwanted voltages above a safe threshold.
voltage stabilizer is an electrical appliance used to feed constant voltage current to electrical gadgets like ACs and computers, and protects them from damage due to voltage fluctuations.
The effects of voltage fluctuations
Explain the effects of voltage fluctuations
The effects of voltage fluctuations
  • You may also notice audio problems such as buzzing or humming noises. As above, it’s common for users to blame this on faulty equipment and replace a perfectly good system when in-depth troubleshooting might have resolved the problem.
  • PC interference and malfunctions including shutdowns and random network problems. These commonly crop up on computer networks.
  • Data drops and download gaps: If you’re working on a data collection application, you’ll often see interruptions in download progress and/or missing data after transfers are supposedly complete. This is especially irritating in remote monitoring applications where transfers need to be reliable so all parties are on the same page.
  • Power quality problems with electronic equipment such as voltage drops, equipment failure, resets, etc. These are notoriously difficult to diagnose, so we recommend using a power data logger to see if the issue actually stems from dirty power or another source.
  • Inaccurate readings and data from signal noise can negatively affect your whole process or research, and you might not notice the errors if you weren’t aware there was a signal problem in the first place. This symptom is especially a threat to industrial processes given the sensitivity of newer electrical equipment.
  • You might encounter video problems on your displays, such as stripes and bars. It’s easy to misdiagnose this symptom as a sign of old or defective equipment, but the cause may actually be more complicated and originate in your facility’s grounding and wiring.

The utility programs
Define utility programs
Utility software is a special program that performs commonly used services that make certain aspects of computing go on smoothly. Such services include sorting ,copying ,file handling, disk management etc
There are two basic types of utility software;
  • i) System level utility: helps the user to work with OS and its functions. example utility software tells the user when he enters a wrong command
  • ii) Application level utility: This makes application programs run more smoothly and efficiently.

Backup devices
Types of backup devices
Backup refers to the process of making copies of data or data files to use in the event the original data or data files are lost or destroyed. Secondarily, a backup may refer to making copies for historical purposes, such as for longitudinal studies, statistics or for historical records or to meet the requirements of a data retention policy. Many applications, especially in a Windows environment, produce backup files using the .BAK file extension.
1. Keep It in the Cloud
Big players in the cloud storage field include:
  • iCloud for Apple product users includes 5GB of free storage. Windows users can also sync their files with iCloud Drive.
  • Google Drive is integrated with Android devices. Windows and Mac users can download a desktop application for drag-and-drop capability. The service includes 15GB of free storage.
  • OneDrive is accessible through Windows 10's file explorer. Android and iOS devices access the site through an app. Mac users can download an app from the Mac App Store. OneDrive includes 5GB of free storage space.
  • Dropbox has been around for a while. It offers personal and business subscriptions. The personal account includes 2GB of free data.
  • Free space and affordable upgrades
  • Data secured in a remote location. You can access it anywhere you can reach the internet
  • Secure transmission of data
  • Capacity limitations for free storage
  • The risk of a site closing
  • Must reach the internet to access your backup files
2. Save It to an External Hard Drive
External and portable hard drives connect to one computer at a time. They are usually wired devices, although some have wireless capabilities. Many external and portable drives now come with USB 3.0 capabilities, but your computer must also have USB 3.0 to take advantage of this feature.
  • Easy to use
  • With software, you can schedule backups and never worry about them again
  • Hard disk drives run the risk of failure
  • Solid-state drives have less risk but can be expensive for large-capacity drives
  • Should be stored off-site in case of fire or another catastrophe
3. Burn It to a CD, DVD, or Blu-ray Disc
Once the gold standard in data backup, burning data to CDs, DVDs, or Blu-ray discs is now a much less popular, albeit still reliable, a method of data backup.
  • Drive failure not an issue
  • Can store safely in a second location (safety deposit box, for example)
  • Time-consuming to manage the backups
  • Assumes future of CD-capable technology. Some equipment no longer includes a drive for this purpose.
  • Can get pricey for large amounts of data as you continue to buy additional discs.
4. Put It on a USB Flash Drive
USB flash drives are like tiny solid state drives that you can carry in your pocket. While they were once expensive and available only in small capacities, their prices have dropped and size increased.
  • Affordable
  • Portable
  • Available in USB 3.0
  • Easy to misplace (not recommended for long-term storage of crucial information because of this risk)
  • Not always durable
  • Capacity limitations
5. Save It to a NAS Device
A NAS (network attached storage) is a server that’s dedicated to saving data. It can operate either wired or wirelessly—depending on the drive and your computer— and once configured, it can display as simply another drive on your computer.
  • Can back up several computers at once
  • Can be set for automatic backup
  • Pricey
  • Possibility of drive failure

Computer Is the process of preventing computer data loss
The following are security measures for protecting computer data;
  1. The use of password or encryption
  2. Installing ant-virus
  3. Avoid downloading free games
  4. Shopping on safe or protected websites
  5. Avoid sharing password
The concept of virus
Explain the concept of virus
A virus is a program that infect an executable file
  • File function differently than before
  • May be only displaying a began messages on the monitor
  • May be deleting some or all file on the user's hard drive
  • May be altering data filesnote
  • This is a malicious program that copies itself
Requires human action to propagate it, it never copies itselfCopies itself automatically
Infects an executable filestand alone program
  • This is a deceptively labeled program that contains at and that harms the user.
  • Note: Trojan horse does not replicate , that distinguishes it from viruses and worms.
  • TROJAN HORSE allows a hacker to remotely control the victim's computer
  • Perhaps it collects the password and credit card number and send them to the hacker
  • Perhaps it launches deprival service attacks on websites.
  • This is a program that detonates when some events occurs. the detonated program might stop working( i.e. go to an infinite loop) crash the computer. release a virus, and delete data files or any of many other harmful possibilities.
  • time bomb is a type of logic bomb in which the program detonates when the computer clock reaches some target date.
  • This is a malicious software that hides on a computer without a user knowledge.
  • This is malicious software that installed on your computer by internet advertising that allow them to inundate you with pop up messages.
The ant-virus programs
Use ant-virus programs
Antivirus software is a type of utility used for scanning and removing viruses from your computer
Antivirus software is a class of program designed to prevent, detect and remove malware infections on individual computing devices, networks and IT systems.
While many types of antivirus (or "anti-virus") programs exist, their primary purpose is to protect computers from viruses and remove any viruses that are found.
How antivirus software works
Antivirus software typically runs as a background process, scanning computers, servers or mobile devices to detect and restrict the spread of malware. Many antivirus software programs include real-time threat detection and protection to guard against potential vulnerabilities as they happen, as well as system scans that monitor device and system files looking for possible risks.
Antivirus software usually performs these basic functions:
  • Scanning directories or specific files for known malicious patterns indicating the presence of malicious software;
  • Allowing users to schedule scans so they run automatically;
  • Allowing users to initiate new scans at any time; and
  • Removing any malicious software it detects. Some antivirus software programs do this automatically in the background, while others notify users of infections and ask them if they want to clean the files.
Types of antivirus programs
Antivirus software is distributed in a number of forms, including stand-alone antivirus scanners and internet security suites that offer antivirus protection, along with firewalls, privacy controls and other security protections.
Some antivirus software vendors offer basic versions of their products at no charge. These free versions generally offer basic antivirus and spyware protection, but more advanced features and protections are usually available only to paying customers.
While some operating systems are targeted more frequently by virus developers, antivirus software is available for most OSes:
  • Windows antivirus software. Most antivirus software vendors offer several levels of Windows products at different price points, starting with free versions offering only basic protection. Users must start scans and updates manually and typically free versions of antivirus software won't protect against links to malicious websites or malicious attachments in emails. Premium versions of antivirus software often include suites of endpoint security tools that may provide secure online storage, ad blockers and file encryption. Since 2004, Microsoft has been offering some kind of free antivirus software as part of the Windows operating system itself, generally under the name Windows Defender, though the software was mostly limited to detecting spyware prior to 2006.
  • macOS antivirus software. Although macOS viruses exist, they're less common than Windows viruses, so antivirus products for macOS are less standardized than those for Windows. There are a number of free and paid products available, providing on-demand tools to protect against potential malware threats through full-system malware scans and the ability to sift through specific email threads, attachments and various web activities.
  • Android antivirus software. Android is the world's most popular mobile operating system and is installed on more mobile devices than any other OS. Because most mobile malware targets Android, experts recommend all Android device users install antivirus software on their devices. Vendors offer a variety of basic free and paid premium versions of their Android antivirus software including anti-theft and remote-locating features. Some run automatic scans and actively try to stop malicious web pages and files from being opened or downloaded.
Virus detection techniques
Antivirus software uses a variety of virus detection techniques.
Originally, antivirus software depended on signature-based detection to flag malicious software. Antivirus programs depend on stored virus signatures -- unique strings of data that are characteristic of known malware. The antivirus software uses these signatures to identify when it encounters viruses that have already been identified and analyzed by security experts.
  • A virus signature (also known as a virus definition) is a file or multiple files that are downloaded by a security program to identify a computer virus.
The effects of dust, liquid, temperature and humidity on a computer and accessories
Explain the effects of dust, liquid, temperature and humidity on a computer and accessories
Keeping a clean environment in your home or office is good for the performance and longevity of your computer. Environmental factors like dust, smoke and spilled liquids can damage your computer in ways that you may have not considered. Let’s take a look at a few of these dangers in your workspace.
Dust: Most computers are designed to use a combination of vents and cooling fans to keep the internal components operating a safe temperature. While dust on the outside of your computer case can’t cause much damage, once dust is drawn into those vents they can begin to clog. When the vents clog the fans have to work harder to maintain a safe temperature. Additionally, dust that settles on the inside of your computer has unwanted insulating properties and can blocking proper airflow. Like any mechanical part, the harder those internal cooling fans work the faster they will break. If the fans are unable to maintain a safe temperature, other parts of your computer like the memory, processor or power supply can overheat and stop working correctly.
Smoke: Believe it or not, cigarette smoke can be bad for your computer. Smoke of all kinds contains particulate matter that be drawn in your computer just like dust. The sticky tar in smoke that damages your lungs can also build up on the internal parts of your computer, putting your computer at risk for overheating or even short circuits of the delicate electrical components. Naturally this doesn’t just apply to cigarette smoke. If your computer is next to a wood stove, an ashtray or a fireplace you may want to consider relocating it to another location.
Cold Temperatures, cold temperatures are not as dangerous to a computer as overheating is, but problems can still occurs. If computers get too cold when left powered off, their components can be damaged upon boot because the electricity heats the circuit. As electricity travels through an circuit, it heats rapidly and causes the matter to expand. Rapid expansion, when close to matter that remains the same size, it distorts it. This can bend or break component.s Therefore, you should let computers previously stored in cold temperatures heat to room temperature before turning them on. Laptop displays are especially vulnerable to cold weather; they have liquid crystal that can freeze. Therefore, the laptop needs to be at or close to room temperature before powering up
Overheating, laptop and desktop computers are vulnerable to overheating. The electronic components operate at a specific current induced by a low voltage. The sensitivity of the components means that even a small fluctuation in voltage is dangerous. Excessive heat lowers the electrical resistance of objects, therefore increasing the current. In addition, slowdown is a result of overheating. Components can shut down when overheated and the motherboard temperature sensor instructs hardware such as the hard drive and processor to slow down.
Humidity, during normal use, humidity doesn't pose as likely a threat as heat. Everyone knows that electronics and water don't mix, but as long as you don't spill liquid into your computer, humidity is unlikely to break it. That said, both extremely humid and extremely dry climates can cause problems.
Temperature Limits, computer components have differing heat safety thresholds, often listed in the part's specifications. The most likely part to overheat, the CPU, automatically throttles its speed if it approaches its maximum temperature. If it continues to overheat, it triggers a fail safe which shuts down the computer rather than risk permanent damage. Maximum temperatures -- sometimes called if you're concerned about overheating.