[<< wikibooks] K-12 School Computer Networking/Chapter 3
By Jennifer Williams-Onyeulo

== Computer Operating Systems ==

== Introduction ==
An operating system is the core element of a computer system. It is the most important software that runs on a computer. It creates an interface so that users are able to interact with the computer hardware. Simply put, you need an operating system, otherwise, your computer is deemed useless.

==== Diagram ====

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The three main operating systems for personal computers are Windows, Mac OS X and Linux. Microsoft remains the most popular of the operating system. Mac OS X was developed by Apple for their Macintosh computers. Linux started out as a college student hobby and has grown into a very comprehensive and growing operating system. It became popular because it is both free and open source software.

All of these operating systems have pros and cons. However, they are all similar and buying the right one is all about personal preference.

== Choosing an Operating System ==
When you decide to buy a new computer system or upgrade your existing operating system you have to ensure that you make the right choice. This is the most important component of your computer that runs all the other programs you have on your computer. Therefore you should make certain that it will be compatible with the software that you want to use.

You should think to yourself, "What will I need from my operating system? Do I need it to run video and image editing applications, or do I need it to run word processing applications? Is it secure enough to withstand hackers? How does the cost compare with other operating systems? Another thing to consider is how will it be maintained and whether software is available.

http://www.youtube.com/watch?v=y29ej5XydTo YouTube Video

Making the Break from Windows to Linux

== Advantages and Disadvantages of the Major Operating Systems ==
No operating system is perfect, each has its advantages and disadvantages. Let's look at each operating system and identify some of its advantages and disadvantages.

Mac OS X is great for keeping out hackers and for graphic design and video editing. However, some software is still not available for Macs. If the software is for Video and Image editing then clearly Mac would be the choice. 

Windows score lower points than the others in terms of security, it is very good for compatibility. There are lots of software and hardware on the market that is compatible with windows. Windows also comes with applications already installed. On the other hand, it is weak against viruses and can get bogged down easily. 

Linux, can be obtained for free and it is completely customizable. However, one major drawback is the extreme scarcity of applications for it. Microsoft and other software developers are often very reluctant to release their products for Linux. 

Each operating system will have its advantages over the competition so you need to do thorough research in order to get the best, based on your needs. If you never use a Mac before, visit an apple store and play with it or go to their website http://www.apple.com/mac/

If you never use Windows, go to a computer store and play with it or go to their website to learn more about it. http://www.microsoft.com/windows/

For Linux you can download a live CD distribution for Linux and burn a version of Linux, install it and play with it. Otherwise go online to learn about it http://www.linux.org/ 

Last but not least, check with other Technical Coordinators in your district. Visit a school and see what operating system they are using and note what problems they are having, if any.

== Securing Your Operating System ==
No matter what applications you are running on your operating system, It should be secured to avoid any conflict or leak of data. 

Here are some guidelines for securing Your operating system


Keep your system and software up to date:
This is one of the easiest, most effective things you can do to keep your computer secure. You can either update manually with Windows Update, or configure your systems to download updates automatically from Windows website

Install antivirus software:
The vast majority of viruses are designed to affect Windows systems. Get site-licensed antivirus software that is configured to automatically update itself and protect your system. 

Install anti-spyware software:
Many of the nuisance-level problems affecting Windows computers are caused by spyware rather than viruses. Spyware can cause effects ranging from a noticeable slowing of your computer to pop-ups and hijacked web browsers; spyware can also be malicious, reporting personal information from credit cards to passwords to other unauthorized websites.

Install Service Pack 
Install appropriate Service Pack for your operating system. This offers several security enhancements and tools such as firewall and a security configuration wizard to check the system's security.

Use Manage your Server for server operating systems to enable only the services you need. This tool is found in the server administration area of your system.

Choose a good password 
Any computer that will have multiple useers or attached to a network needs to have good password protection for each user. Make sure that all user accounts on your network has a password. A blank password will allow anyone to login to the network simply by clicking.

Use the Microsoft Baseline Security Analyzer (MBSA) to detect and correct common security misconfigurations. Microsoft provides a tool called the Microsoft Baseline Security Analyzer (MBSA) to assist with detecting potential security flaws and correcting them. The MBSA tool checks for issues such as missing patches, user accounts without passwords, available updates to installed Microsoft software, and more. 

Don't give out too many "administrator" group memberships:
The Administrator account is the most powerful account on a Windows system. Most users shouldn't log in with administrator privileges for everyday work; the administrator privileges should be reserved for actions such as installing software and patching the system. 

If only the administrator and guest accounts have been created on the computer, you should create an individual user name so that you can have a regular account for daily use without administrator privileges.

However, make sure that the administrator account does still have administrator privileges; it's important that at least one user has that ability at all times. 

Disable unnecessary services and accounts:
Because each service and account represents a potential entry point to your computer, disabling the features you don't use will greatly diminish your exposure to security risks. Remember, you can always enable a service later if you decide you really do need it. You can enable and disable services with the Manage Your Server tool. 

Securing Your Mac OS System

Keep your system and software up to date:
This is one of the easiest, most effective things you can do to keep your computer secure. The automatic update tool can be found in System Preferences under the apple menu in the top left corner of your screen. Click Software Update, and then choose whether you want to update manually or automatically.

Install antivirus software:
While Mac OS is not as susceptible to viruses as some other operating systems, you should still install antivirus software to help alert you to viruses in email messages or downloads. Even if the virus doesn't affect Mac OS, you don't want to pass it on to friends, family, or colleagues who may be using a different operating system. Virex (antivirus software for Macs) is a popular antivirus software.

Don't run services you don't need:
Each service you run represents a means of access to your computer. That's not inherently bad, but there's no need to expose yourself to unnecessary risks. If you don't need to run a web server on this computer, don't start it up. The list of available services can be found in System Preferences under the Services tab of the Sharing icon. Be cautious of the sharing services; a misconfiguration here could grant full access to personal files or system resources.

Choose a good password:
Any computer that will have multiple users or be attached to a network needs to have good password protection for each user.

Use your personal firewall:

While the firewall included in Mac OS is not nearly as customizable as other software firewalls, it is effective in reducing the amount of network traffic that is allowed to reach your computer. Open System Preferences and click the Sharing icon. Next, click the Firewall tab and then click Start. 

Limit administrative access:
Mac OS allows you to designate certain users as system administrators. These users are allowed much greater access to the system, meaning that care should be taken when granting these privileges. If a user doesn't need to modify the system's settings, there is no reason for that user to have administrative access. All users can modify their own personal preferences. Administrative privileges grant access to system to functions such as services and patches.

Securing Your Linux Operating System:
There are many variants to the Linux operating system. Here is a website that will give you information on how to secure your Linux and different versions of UNIX operating systems http://www.cites.uiuc.edu/wsg/resources/security/

You Tube videos on System Break-ins

http://www.youtube.com/watch?v=nDv0-iv3TLA YouTube video
http://www.youtube.com/watch?v=Qnv_oxV4tGU&feature=related YouTube video

== Surviving a Disaster: What's Your Backup Strategy ==
Windows Server using Active Directory 
Windows Server 2003





== Next Generation Operating Systems ==

== Challenge! ==
1. What is an operating system? Is it software?

2. You are viewing this chapter on a computer. What operating system is your computer using? 

3. Search the Internet for articles that compare Windows Vista and Mac OS X. What are the differences? What are the similarities?

4. When choosing an operating system, what are some of the things you should consider?

== Answers to Quiz ==
Question 1

The operating system is the software that controls the computer. Without it the computer would not be able to start. 

It controls the memory needed for computer processes, manages disk space, controls peripheral devices, and allows you to communicate with the computer without knowing exactly how a computer works. 

It is labeled software because software is a set of instructions that performs some task on the computer. The Operating system is the boss of all software on a computer.

Question 2

Various answers.

Use these links to find out more about your operating system





Question 3

Various answers. Use this link to check your answers http://wiki.answers.com/Q/What_are_the_similarities_and_differences_between_Macs_and_PCs

Question 4

Consider what the operating system will be used for. Conduct a thorough research and visit other technical coordinators to see first hand how their operating system is keeping up. In addition, visit vendors and test-drive more than one operating system.

== You Tube Video: Interview with Kevin Gole - Veteran Teacher/Technology Coordinator ==

Jennifer interviews Kevin, a veteran teacher and technology coordinator at an elementary school in New York City, to learn about his role as a technical coordinator and how he balances this role with his teaching responsibilities

== References ==

2. http://www.youtube.com/watch?v=y29ej5XydTo

3. http://www.computerhope.com/issues/ch000575.htm

4. http://www.apple.com/mac/

4. http://www.microsoft.com/windows/

6. http://www.linux.org/

7. http://update.microsoft.com/windowsupdate

8. http://www.cites.uiuc.edu/wsg/resources/security/

9. http://www.youtube.com/watch?v=nDv0-iv3TLA


11. http://technet.microsoft.com/en-us/magazine/cc462796.aspx

12. http://www.computerperformance.co.uk/w2k3/disaster_recovery_backup.htm

13. http://www.macworld.com/article/57131/2007/04/oldmac_backup.html

14. http://www.halfgaar.net/backing-up-unix 

15. http://userpages.umbc.edu/~jack/course/backups.html