Welcome to this week's edition of the Computer Kindergarten Newsletter.
Today is Sunday, March 17, 2013
In this Issue:
Special Feature: Computer Viruses
Special Series: Twenty Things I Learned About Browsers and the Web: Browser Extensions
This Week's Topic: Speed Up a Slow Computer – Detect and Repair Disk Errors
Special Feature: iPad Basics - Notifications
Websites of Interest: St. Patrick’s Day; Brain Games; Sprout Robot; Return to Mars; International Day for the Elimination of Racial Discrimination
Special Feature: Computer Viruses
Worms, trojan horses, macro viruses, boot sector viruses....it can be rather dangerous to be a computer user these days, especially if you share data with other people or download software from the Internet. The danger isn't exactly targeted towards you, but towards your data, which, in some cases, can be destroyed.
A virus is just a computer program. Like any other program, it contains instructions that tell your computer what to do. But unlike an application, a virus usually tells your computer to do something you don't want it to do, and it can usually spread itself to other files on your computer--and other people's computers.
A virus is a program or piece of code (computer instructions) that is loaded onto your computer without your knowledge and runs against your wishes. Viruses can be hidden in executable program files posted online, secreted in mail attachments or can be distributed in other ways.
If you're lucky, a virus will execute only a benign personality quirk, such as causing your computer to make seemingly random bleeps. But a virus can also be very destructive; it could format your hard drive, overwrite your hard drive boot sector, or delete files and render your machine inoperable.
Most viruses can also replicate themselves. They can spread swiftly across open networks such as the Internet, causing billions of dollars worth of damage in a short amount of time. All computer viruses are manmade. A simple virus that can make a copy of itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and bring the system to a halt. An even more dangerous type of virus is one capable of transmitting itself across networks and bypassing security systems.
Since 1987, when a virus infected ARPANET, a large network used by the Defense Department and many universities, many antivirus programs have become available. These programs periodically check your computer system for the best-known types of viruses
Some people distinguish between general viruses and worms. A worm is a special type of virus that can replicate itself and use memory, but cannot attach itself to other programs.
A Trojan horse is a destructive program that masquerades as a benign application. Unlike viruses, Trojan horses do not replicate themselves but they can be just as destructive. One of the most insidious types of Trojan horse is a program that claims to rid your computer of viruses but instead introduces viruses onto your computer.
The term comes from a story in Homer's Iliad, in which the Greeks give a giant wooden horse to their foes, the Trojans, supposedly as a peace offering. But after the Trojans drag the horse inside their city walls, Greek soldiers sneak out of the horse's hollow belly and open the city gates, allowing their fellow soldiers to pour in and capture Troy.
A macro virus is a type of computer virus that is encoded as a macro** embedded in a document. Many applications, such as Microsoft Word and Excel, support powerful macro languages. These applications allow you to embed a macro in a document, and have the macro execute each time the document is opened. Once a macro virus gets onto your machine, it can embed itself in all future documents you create with the application. Antivirus programs can protect your system against most macro viruses, although new ones are always being created that slip by the antivirus filters.
**a macro is a symbol, name, or key that represents a list of commands, actions, or keystrokes. Many programs allow you to create macros so that you can enter a single character or word to perform a whole series of actions. You can also use macros to enter words or phrases that you use frequently. For example, you could define a macro to contain all the keystrokes necessary to begin a letter -- your name, address, and a code that inserts the current date. Then, whenever you write a letter, you just press the macro key to include the letter header.
Boot sector infecting viruses are one of the most common types of viruses around. A boot sector is a special location on all disks, hard or floppy, where the Basic In/Out System (BIOS) of a computer looks during the booting of a computer for a bootable system. The boot sector of a disk stores instructions that identify the partition on a disk, contains startup files, etc.Boot sector viruses put viral code (instructions) into the boot sector of a disk. When the computer is booted (turned on), the viral code is executed, putting the virus into memory and infecting the hard drive master boot sector.
Once infection of the master boot record of the hard disk occurs the virus is run in memory each time the computer is booted from the hard drive. All disks used on the computer from that point forth have their boot sector infected with the virus code. This leads to proliferation to other systems or reinfection of a cleaned computer at a later date.
There are ways to protect your computer from viruses. First, read this article to understand what viruses are and how they work. Second, equip your computer with a reliable anti-virus software program.
Anti-virus programs come with a database of information on thousands of known viruses. The program looks through all the data on your hard drive to see if anything matches a pattern in that database. Since new viruses are constantly appearing, you must update your anti-virus program regularly. Most anti-virus software publishers release updates to their software containing information on new viruses every few months. By downloading a small driver file used with the software, you'll have maximum protection against new viruses and Trojan Horse programs.
A Trojan Horse is a program that appears to perform a valid function but contains, hidden in its code, instructions that cause damage (sometimes severe) to your computer. Trojan Horse programs may compromise the security of an Internet account, contain objectionable graphics, or cause damage to your computer files.
Not all anti-virus software programs protect you from Trojan Horse programs. However, you can easily avoid Trojan Horse programs by NEVER downloading a file attached to an e-mail from someone you don't know. Some email providers help you remember this with an automatic warning system. If you start to download a file type that is typically associated with Trojan Horse programs, you will receive a warning message. You may then decide to proceed with the download or cancel it. If you don't know the sender, don't download the file!
There are thousands of viruses in circulation. Here are some tips to protect you from infecting your computer:
* Don't open E-mail from Strangers: You can get a virus if you download an infected file attached to an e-mail message. Here's a simple rule: If you don't know the sender, don't download the attachment -- no matter how interesting it may appear to be.
* Watch the Net: Exercise caution if you download files from the Internet. Look for a statement at the site saying that its files have been checked by an anti-virus program. Downloading from a legitimate site that checks its files for viruses is likely to be safe. If the files haven't been checked, or if you're not sure, then either download the file to a disk and check it with your own anti-virus software or don't download from that site at all.
* Spread the Word: Sure, you practice safe surfing, but what about the other members of your household? You can't watch your teenager every minute. Will the allure of a new program or game be more than they can stand? Will they download a file and then run it before scanning it with an anti-virus program? Share the information in this area with other members of your family and have a discussion about how to keep your computer safe from viruses.
* Check your Disks and External Drives: Another way viruses spread is by infected disks and USB drives. If you bring work home from the office, you could bring a virus home, too. Scan all your disks to make sure they're safe. (You might also consider e-mailing files to yourself at home instead of bringing them via disk.)
* Back it Up: The best way to protect the data on your computer is to back it up on a regular basis. There are lots of back-up options available these days, from disks to high capacity external drives. If a virus slips through your defenses, a back-up will let you replace files destroyed by the infection.
* Stay Current: Because new viruses are being created all the time, you've got to keep your anti-virus software up to date. Look for updates containing information on new viruses from the software's publisher.
* Arm Your Computer: Of course, the best way to protect yourself against viruses is to be armed with potent anti-virus software.
If you think you have a virus, follow this checklist:
1. Stop using the computer: You should never try to do normal work on an infected computer. Don't try to delete files you think may be infected -- it's unlikely that you'll get rid of the virus that way. If possible, exit all your programs and shut the computer down normally, don't just hit the "off" switch.
2. Don't use any disks or external drives: Don't risk spreading the virus to someone else. Many viruses are transferred from computer-to-computer on disks. Never put a disk into a computer you think may be infected.
3. Confirm the presence of a virus, then get rid of it: Just because you're having a problem doesn't mean your computer has a virus. You may have a hardware problem. No matter what, run a virus-checking program to identify and remove any viruses.
4. Scan all disks and external drives: If you've confirmed the presence of a virus, scan all your disks and drives with the anti-virus software to make sure they're not infected too. You wouldn't want to clear out the virus only to have a disk re-infect your computer!
Special Series: Twenty Things I Learned About Browsers and the Web: Browser Extensions
Many of us these days depend on the World Wide Web to bring the world’s information to our fingertips, and put us in touch with people and events across the globe instantaneously.
These powerful online experiences are possible thanks to an open web that can be accessed by anyone through a web browser, on any Internet-connected device in the world.
But how do our browsers and the web actually work? How has the World Wide Web evolved into what we know and love today? And what do we need to know to navigate the web safely and efficiently?
“20 Things I Learned About Browsers and the Web” is a short guide for anyone who’s curious about the basics of browsers and the web. Here’s what you’ll find here:
First we’ll look at the Internet, the very backbone that allows the web to exist. We’ll also take a look at how the web is used today, through cloud computing and web apps.
Finally, we’ll look ahead to the exciting innovations in browsers and web technologies that we believe will give us all even faster and more immersive online experiences in the future.
Life as citizens of the web can be liberating and empowering, but also deserves some self-education. Just as we’d want to know various basic facts as citizens of our physical neighborhoods -- water safety, key services, local businesses -- it’s increasingly important to understand a similar set of information about our online lives. That’s the spirit in which we wrote this guide. Many of the examples used to illustrate the features and functionality of the browser often refer back to Chrome, the open-source browser that we know well. We hope you find this guide as enjoyable to read as we did to create.
The Google Chrome Team
Browser extensions let you add new features to your browser — literally extending your browser.
This means that you can customize your browser with the features that are most important to you. Think of extensions as ways of adding new superpowers to what the browser can already do.
These superpowers can be mighty or modest, depending on your needs. For example, you might install a currency converter extension that shows up as a new button next to your browser’s address bar. Click the button and it converts all the prices on your current web page into any currency you specify. That’s helpful if you’re an avid backpacker who does most of your travel planning and booking online. Extensions like these let you apply the same kind of functionality to every web page you visit.
Browser extensions can also act on their own, outside of web pages. An email notifier extension can live on your browser toolbar, quietly check for new messages in your email account and let you know when one arrives. In this case, the extension is always working in the background no matter what web page you’re looking at — and you don’t have to log in to your email in a separate window to see if you have new messages.
To discover new extensions, check out your browser’s extensions gallery. You’ll see thousands of extensions that can help make browsing more efficient or just plain fun — from extensions that let you highlight and scribble notes on web pages while you’re doing research, to those that show nail-biting, play-by-play sports updates from your browser’s interface.
In out next edition: Synchronizing the Browser
Today's Topic: Speed Up a Slow Computer – Detect and Repair Disk Errors
As your Windows computer ages, its speed can decrease. You will notice an increase in response time when you give commands to open programs, files or folders, use the Internet and other tasks. There are several things you can do to speed up your computer.
In our ongoing series, Speed Up a Slow Computer, we will present articles discussing some of the steps you can take to speed up your slow computer.
Important: Before making any changes to your system, always create a Restore Point. If anything goes wrong with the changes you make, this will allow you to revert back to a point when the computer was operating correctly. Please visit our Newsletter Archives to read our article, All About Restore Points:
Detect and Repair Disk Errors
As a computer gets older, parts of the hard drive can begin to develop errors. Disk usage and improper shutdowns can cause what are called bad sectors. This kind of error takes up disk space and can lead to slow performance.
Windows includes a tool called CheckDisk or Disk Checker (depending on your version of Windows). It searches the disk for errors and bad sectors and attempts to fix them. To use CheckDisk, follow these steps:
Open My Computer or Computer. My Computer is found in Windows XP and Computer is found in Vista and 7. Look for the icon on the desktop or in the item in the Start menu.
Right click on the C: drive. Click Properties in the resulting menu.
Click the Tools tab at the top.
Click the Check Now button.
Click to select the Scan for and attempt recovery of bad sectors check box and click Start.
This will check the hard disk and, if possible, repair any errors it finds.
In our next edition, Speed Up a Slow Computer – CCleaner
Special Feature: iPad Basics - Notifications
Notifications are pop-ups, banners, and other audio/visual cues that work with the apps on your device. They're designed to let you know when something needs your attention, or when there's been any recent activity (for example, on Facebook).
Notifications behave differently in each app, but they all have one thing in common: they can be a huge benefit to keeping up with everyday tasks and responsibilities. You can receive notifications three different ways:
Via the Notification Center
As an alert (a pop-up or banner)
As a badge on the app icon itself
Many apps generate notifications automatically. You'll learn over time which ones do, and which ones don't.
The Notification Center is where you'll view most of the notifications on your device. It's a great place to check in every now and then, because it summarizes the activity on your iPad (rather than alerting you to each item one by one). Many apps are set up to display updates this way by default.
To open the Notification Center, swipe down from the top of your screen. To go to the source of a notification, tap the one you want.
Alerts can be set up to display a banner or pop-up whenever there's new activity. They impart a little more urgency than the Notification Center, so they might be a good choice for apps that are especially important to you. For example, you could set up alerts to let you know whenever a reminder is due.
Badge App Icon
Ever noticed a little red number attached to one of your favorite apps? Don't be alarmed—that's just the badge app icon, a feature designed to let you know when there's a notification waiting inside.
The badge means different things depending on the app. For example, in Facebook, it could mean that you've just received a new friend request. In the App Store, it could mean that you have an update waiting for one of your current apps. The badge will go away once you view the notification.
In our next edition:
Websites of Interest:
St. Patrick’s Day
Although not much of it is actually substantiated, much Irish folklore surrounds St. Patrick’s Day. Learn about traditions, customs and history at this website:
Want to learn how to make a great Irish stew or potato soup or, better yet, Irish coffee? Visit this website:
Intellectually stimulating free puzzle games.
Enter your zip code to get the timing for planting flowers and veggies.
Return to Mars
Learn about Curiosity, NASA’s rover, landing and exploring Mars.
International Day for the Elimination of Racial Discrimination
How nice it would be if all bigotry was eliminated from the world!