PC Maintenance Class 4

We covered two topics that we started on last week, splitting the session in two, a lecture type discussion on Windows Security, and a hands on practical session involving what I referred to as a 'problematic' laptop.

We had discussed the various types of virus that can effect Windows computer, and we dug further into this subject by touching on this again with a presentation on general security, concentrating on online security. We covered the topics of Cyberbullying, Phishing, Online fraud, Spam, Protecting your identification.

Cyberbullying is the use of the Internet and related technologies to harm other people, in a deliberate, repeated, and hostile manner. As it has become more common in society, particularly among young people, legislation and awareness campaigns have arisen to combat it.

One of the key factors in looking after your computer, as mentioned in the presentation was to make sure your computer is updated with Windows Update and that you take every effort to backup the machine. This being the case, we then switched briefly to our hardware project. The laptop from last week. Having taken the laptop away to attempt to get the user data off it and failed,  we were faced with having to do a factory restore.

The first thing I needed to do was alter what is known as the computer's Boot Sequence. This is done by entering the BIOS menu, upon boot. This process is known as booting, or booting up, which is short for bootstrapping.

The BIOS software is built into the PC, and is the first code run by a PC when powered on ('boot firmware'). When the PC starts up, the first job for the BIOS is to initialise and identify system devices such as the video display card, keyboard and mouse, hard disk drive, optical disc drive and other hardware. The BIOS then locates boot loader software held on a peripheral device (designated as a 'boot device'), such as a hard disk or a CD/DVD, and loads and executes that software, giving it control of the PC.

BIOS software is stored on a non-volatile ROM chip on the motherboard. It is specifically designed to work with each particular model of computer, interfacing with various devices that make up the complementary chipset of the system. In modern computer systems the BIOS chip's contents can be rewritten without removing it from the motherboard, allowing BIOS software to be upgraded in place.

In the BIOS menu, I had to set the DVD drive as the first boot device, so that when I put the Recovery DVD in the drive, the computer would boot up from the optical disk rather than the C: drive.  The further settings of BIOS is something we will look at in a later class. Understanding it, can help you learn more about how the computer works, however changing settings in it, can be at the detriment of your computer if you are a novice. By all means have at look at your computer's BIOS settings, but don't change anything if you are unsure.  Entering setup on most machines involves pressing something like F2 or DEL, this is usually presented on screen briefly before Windows loads.

Continuing, the machine booted up, and the Recovery process was able to start 'recovering the computer' to its factory settings.

Jumping back into the subject of Backups, we then finished the sesssion, by looking at how the automated Backup and Restore Centre in Windows 7 works. 

The Windows 7 Backup and Restore centre.

Backup and Restore is run through the Windows Control Panel.  One of the first things I pointed out, was the ability to make a Windows System Repair Disk. This involves placing a blank disk into the computer and allowing Windows to make the disk for you. To make one, or more information, click the link below...

• Making a Windows System Repair Disk

One of the other function available, which we will look at next time, is the option to create a System Image, information on this can be found by clicking the link below. In a nut shell though, the System Image is used in conjunction with the System Repair Disk to do a full system restore. Usually the System Image is best stored on external USB Harddisk, but can be spanned across multiple DVDs depending on the amount of data on your computer.

• What is a Windows System Image?

Setting your computer to backup on a schedule is dead easy. For the first time you click on Set up Backup. And simply follow the wizard. If you have an external drive plugged into your computer (which is the preferred means of backup) it will automatically identify it. The next screen will ask 'what' you want backed up, then finally, you are able to set the time and frequency of the backup. The default is every Sunday at 19:00.  I decided to set the laptop in class to backup everyday at 22:00.

This is an external USB drive.  This particular model is one of the Seagate FreeAgent Go range. Powered through the one USB cable, it just plugs into a free USB port on your computer, 
and simply appears in My Computer.

The first backup takes some time, it copies everything you selected, however subsequent daily backups, in this scenario, are incremental, and only the differences are backed up, making the daily task of backing up, minimal. Then once a month a new 'backup set' is created and is stored seperate to the first, this continues the cycle until the backup drive is full, and then the oldest backup set is deleted.  Progress and details of backups can be reviewed in the main screen of the Backup and Restore centre.

After Half Term, because we are away next week, we will look at those settings and explore how we can manage our backups, and most importantly, how we restore data if we lose it!

See you in a fortnight!

PC Maintenance Class 3

Tonight's class was split into three parts. Firstly, Anti-Virus, then Printer Troubleshooting and finally a practical session with a problematic laptop.

Click this hyperlink to download a copy of the presentation I used in class tonight!

Anti-virus is very important piece of software to have on your computer, there are many types of viruses out there that infect PCs all around the world. It's critical to make sure your Anti-virus software is up to date and current. That usually means if its older than a week, then its no good!

Strange as it may sound, the computer virus is something of an Information Age marvel. On one hand, viruses show us how vulnerable we are -- a properly engineered virus can have a devastating effect, disrupting productivity and doing billions of dollars in damages. On the other hand, they show us how sophisticated and interconnected human beings have become.

Experts reckon MyDoom worm infected approximately a quarter-million computers in a single day in January 2004. Back in March 1999, the Melissa virus was so powerful that it forced Microsoft and a number of other very large companies to completely turn off their email systems until the virus could be contained. The ILOVEYOU virus in 2000 had a similarly devastating effect. In January 2007, a worm called Storm appeared -- by October, experts believed up to 50 million computers were infected. That's pretty impressive when you consider that many viruses are incredibly simple.

When you listen to the news, you hear about many different forms of electronic infection. The most common are:

• Viruses - A virus is a small piece of software that piggybacks on real programs. For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc.
• E-mail viruses - An e-mail virus travels as an attachment to e-mails, and usually replicates itself by automatically mailing itself to dozens of people in the victim's e-mail address book. Some e-mail viruses don't even require a double-click -- they launch when you view the infected message in the preview pane of your e-mail software.
• Trojan horses - A Trojan horse is simply a computer program. The program claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk. Trojan horses have no way to replicate automatically.
• Worms - A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.

Discussing printers and how to troubleshoot them, we concentrated on the two main types of printer that are widely available Inkjet and Laser, although we mentioned a third, and older generation of Dot Matrix Printers.

No matter where you are reading this blog, you most likely have a printer nearby and there's a very good chance that it is an inkjet printer. Since their introduction in the latter half of the 1980s, inkjet printers have grown in popularity and performance while dropping significantly in price.

An inkjet printer is any printer that places extremely small droplets of ink onto paper to create an image. If you ever look at a piece of paper that has come out of an inkjet printer, you know that:

• The dots are extremely small (usually between 50 and 60 microns in diameter), so small that they are tinier than the diameter of a human hair (70 microns)!
• The dots are positioned very precisely, with resolutions of up to 1440x720 dots per inch (dpi).
• The dots can have different colours combined together to create photo-quality images.

Laser Printers work completely different. The primary principle at work in a laser printer is static electricity, the same energy that makes clothes in the dryer stick together or a lightning bolt travel from a thundercloud to the ground. Static electricity is simply an electrical charge built up on an insulated object, such as a balloon or your body. Since oppositely charged atoms are attracted to each other, objects with opposite static electricity fields cling together.

A laser printer uses this phenomenon as a sort of "temporary glue." The core component of this system is the photoreceptor, typically a revolving drum or cylinder. This drum assembly is made out of highly photoconductive material that is discharged by light photons.

Initially, the drum is given a total positive charge by the charge corona wire, a wire with an electrical current running through it. (Some printers use a charged roller instead of a corona wire, but the principle is the same.) As the drum revolves, the printer shines a tiny laser beam across the surface to discharge certain points. In this way, the laser "draws" the letters and images to be printed as a pattern of electrical charges -- an electrostatic image. The system can also work with the charges reversed -- that is, a positive electrostatic image on a negative background.

After the pattern is set, the printer coats the drum with positively charged toner -- a fine, black powder. Since it has a positive charge, the toner clings to the negative discharged areas of the drum, but not to the positively charged "background." This is something like writing on a soda can with glue and then rolling it over some flour: The flour only sticks to the glue-coated part of the can, so you end up with a message written in powder.

With the powder pattern affixed, the drum rolls over a sheet of paper, which is moving along a belt below. Before the paper rolls under the drum, it is given a negative charge by the transfer corona wire (charged roller). This charge is stronger than the negative charge of the electrostatic image, so the paper can pull the toner powder away. Since it is moving at the same speed as the drum, the paper picks up the image pattern exactly. To keep the paper from clinging to the drum, it is discharged by the detac corona wire immediately after picking up the toner. See...you learn something everyday!

The final part of the class, was a problem laptop. The laptop doesn't start up properly to cut a long story short, so a reinstallation was required. However there was work on the laptop, so we had to try and get the work off the machine first. I had a portable harddisk docking station, of which I placed the removed harddisk from, into it. The problem was though my laptop wasnt reading the drive probably, and time had caught up with us rather rapidly and we had to wrap up and leave things till next week. Come back next time to read about the outcome!

PC Maintenance Class 2

We finished last week by having a look inside a PC but time was against us and we ran out of time, so tonight we had a full session looking at how the computer was put together with all the various components.

I started off by taking the computer apart and then after break I got two volunteers to reassemble the computer. Words can explain what happened, but here are some photographs that show what went on much better!

PC Maintenance Class 1

Autumn is here, and that means one thing, another new year of Night Classes at Barry Comprehensive!

Welcome to another year of PC Maintenance! This years group has 7 students, and it looks like we are going to have a great time!


Tonight's session like all classes at the beginning of term, started off with an presentation that had an introductory session. The aim of this part of the class is to allow the students to introduce themselves to each other, and for us to share what each and everyone is expecting of the course, and an opportunity for them to tell me their computer experience is. The allows me to pitch the level of the class.

The presentation I used, talked the students through the various aspects of the course that we would be following over the next three terms. Topics that we'll be looking at include: Computer hardware, software, Anti-viruses, Home networking, Wi-fi, Reinstallations, Upgrading, Building a PC from Scratch, Applications, Operating Systems - you name it, we'll cover it! I tell all the students that if there is something specific that they want to do, then to just ask, and we will sort something out!

The second half of the session involved a discussion of all the parts of the computer, and finished with a quick look inside the computer case. Next week we will take the computer apart and then reassemble it!

To download a copy of the presentation I used in class, click here!