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Topics

Fundamentals

Backups and Security

User Accounts

There is always at least one administrative account in all operating systems, Windows, Mac O/S, and Linux.

You should create a general (non-administrative) account to do your daily work

Unfortunately, this will require an extra step of logging in when you boot your computer.

User Account Control

On both Windows and Mac O/S

Pop-up windows requiring an administrative password whenever a program wants to make a change to your computer.

Somewhat of a pain, but very important. Normally you always leave it turned on.

Strong Passwords

Include both upper and lower case, numbers, and symbols if allowed.

Make it long, usually as long as possible. 16 to 20 characters is good if you can. No less than 12 characters.

6 characters from a list of 26 possible characters (lower case letters only) gives you 170,581,728,179,578,208,256 possible passwords, which might be broken by a good cracking program.

12 characters from a list of 62 possible characters (letters and numbers but no symbols) gives you about 8,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 possible passwords.

20 characters from a list of 80 possible characters gives you about 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 possible passwords.

Even the fastest computer would take from now to the end of the Sun's solar system, and far beyond that, to try every password.

Change your passwords regularly.

Every calendar quarter is probably sufficient.

You'll probably want a system to generate passwords, such as inserting a number into the middle of your standard passwords, but don't make the system too easy to guess.

Never use just a word from a dictionary, or a phrase.

A dictionary contains only about 20,000 or so words. That is easy for a cracker program to break.

Never use personal information.

Never use easily guessed information, such as patterns - qwerty, 12345, AaBbCc - or associated information - mypassword, Windows7, laptop_computer

Be aware of Social Engineering techniques.

Tricking you into giving out information, or stealing the information without using a computer.

Strategies (two particularly good ones):

Think of a phrase that means something to you, and use the first letters of that phrase. Add some system to change or add to those letters with numbers and symbols, which will change every quarter according to some (secret to you) pattern. For your high security password, pick another, longer phrase.

Pick a favorite book. Then use some system (secret to you) to pick a page number and line number from that book for each quarter. Use the first three words word in that line, adding some pattern (secret to you) of numbers and symbols to replace the spaces. For your high security password, use the last five words of that line.

An example system to generate passwords:

Use the phrase "all dogs go to heaven", use the first letter of each word: adgth.

Then capitalize the letter whose position number that matches the current quarter, Adgth for first quarter, aDgth the second quarter, adGth the third quarter, etc.

Then insert some number that means something to you, but is not too obvious, after the capital letter - A6792dgth the first quarter, aD6792gth the second quarter, adG6792th the third quarter, etc.

Finally, add some symbols - $A6792*dgth! the first quarter, $aD6792*gth! the second quarter, $adG6792*th! the third quarter, etc. These are the passwords that you will use.

For your high security password, use a completely different phrase that is a lot longer, such as "row, row, row your boat gently down the stream" and a different number, giving $R1227*,r,r,ybgdts! the first quarter, $r,R1227*,r,ybgdts! the second quarter, $r,r,R1227*ybgdts! the third quarter, etc,.

Backup Philosophy

Think of data, programs, and the operating system separately.

Data is by far the most important back up.

Replacing your computer, the operating system, and the programs installed is always possible, but if you totally loose your data it is lost forever.

Make sure you have a way to repair or reinstall the operating system, if necessary.

It's usually best to use the methods your operating system gives you.

Be sure to carefully save all disks or backup drives the operating system creates, and save all registration codes.

Make sure you have a list of the programs installed on your computer, and a way to reinstall them.

Data Protection

Always, always, always have at least 2 copies of your data, and 3 or 4 copies is better.

Your data files will be corrupted sooner or later.

The tragedies happen when both your data and the backup become corrupted, which is surprisingly easy.

Always have 1 copy of your data at a different location.

What if your house burns down?
If you use a "Cloud" service from a reputable company (Apple, Google, Microsoft) your data is safe.

Don't worry about it, it's there, but only as long as you have the password.

Always have Version Backups of your data.

If you didn't realize that there was a corruption of your data when you did your last backup, the corruption will be in that backup also. You will need an earlier backup to properly restore your data.

Professionals do short term backups, such as daily or weekly, and then partially erase them after a month, keeping monthly back-ups to six or twelve months into the past.

The backup programs that come with the operating system, Windows Backup and Macintosh TimeMachine, can backup your data, plus your operating system and installed programs, automatically, but you must activate them.

Program Protection

Keep track of where you got your programs -- historically from CD-ROM's you buy, now mostly from downloads from web sites, increasingly from operating system "Stores".

Always store your CD-ROMs carefully, along with all documentation.

Particularly important are any registration codes, often printed on the case or a paper insertion.

You can go back to the web site to get a downloaded program again, but it will probably be a later version, which you may have to repurchase.

Alternatively, you often can just keep the original downloaded file, and run that again to reinstall the program. Usually it will reinstall the original version, but sometimes it will update a newer version.

If you get your Apps from an operating system's "Store", usually everything is taken care of for you.

Getting an App from a Store is safe in the same way as storing your data on the "Cloud".

Usually, Apps from a Store update themselves as necessary, so you always have the latest version. The Store can simply replace that latest version if needed.

Computer Protection

Use your operating system's method to make a recovery disk or flash drive.

Necessary if your C: drive or Mac drive fails completely.

Both Windows and Mac OS will repair themselves automatically if they can.

Most computers now have a hidden recovery area on the computer's original hard drive, usually called drive D: if you are using Windows.

Most computers also can download repair and update information during the recovery process, if there is an active Internet connection.

Carefully preserve your original disks or download information, particularly any registration codes.

Use a back up program.

Usually the one that comes with the operating system is all that you will need.

They back up both the operating system and your data.

"Windows Backup" is adequate, but takes some user awareness about keeping good versions and choosing what and where to save the information. It tends to keep large backup files.

MacIntosh "TimeMachine" is excellent. It is very easy to use. It automatically keeps "snapshots" and allows you to pick how far you want to go back in time. It is also very efficient.

Pick one backup program and stick with it. Different programs are not compatible. The only way to recover your data is through your original backup program.

Ideally, one copy of your backup must be kept at a different location -- possibly a friend's or relative's house. What if your house burns down?

Scott's backup system -- not necessarily recommended for you.

I don't use a back up program, because I don't want to depend on the program for recovery. It might fail.

I simply keep all my data on a separate external drive as the unencrypted original files.

I then manually make copies of all my data files to three completely separate external drives, making four copies of the original files.

I use the Open Source file copy program called "FreeFileSync". It is excellent and only backs up files that have changed, but takes some skill in setting exactly what files should be backed up and where.

I make one of the copies only about every three or four months, and keep it in a fireproof safe.

I don't backup my operating system or programs, because I upgrade Windows or rebuild my computer about every one to two years anyway.

Disadvantages:

Every time I save a file, I have to click to the correct drive and directory before I can press "Save".

I have to remember to do my backups, and spend the time to actually do them.

I had to buy four separate external hard drives to protect the data that will fit on one.

I had to set up the system, which took some skill about drives, directories, and file copy programs.

I still don't have my data in a separate location. If my house burns down and water from the fire hoses gets into the fireproof safe, I would loose everything.

If my operating system crashes, or my C: drive fails, I must completely reinstall Windows and my programs from scratch, about a two or three day job.

Malware Protection

"Malware" is any computer code that will harm your system. It includes "viruses" and "worms", as well as obnoxious advertising pop-ups or spying programs. They will be covered more extensively in the "1's and 0's Flying Through the Air" course.

Only a problem for Windows. Mac OS and Linux are very secure, although Malware is possible on those systems.

Most problems come through the Internet -- both websites and e-mails.

Never, never, click on a link in an e-mail. The whole e-mail message may be a clever phony.

Often there is absolutely no way to tell if an e-mail message is legitimate. Everything about an e-mail can be faked, including the address where it came from. The e-mail system was created before the Internet, when security was not a problem.

Always go directly to the home page of the company you are interested in, and find the information there.

Allowing a website to install a program on your computer can be dangerous.

There are reputable download sites, such as CNET, PCMag and TuCows.

It's also safe if you specifically went to a trusted company's website to do a download.

Malware in Microsoft Office documents is also a common problem, unless you know the document comes from a trusted source.

Be sure to follow User Account Control on both Windows and Mac.

User Account Control is the pop up window from the operating system that requires an administrative password to make any significant changes to your computer.

Best practice is to have a separate User Account without administrative privileges for your everyday use.

User Account Control is turned on by default when you install Windows or Mac OS and you should leave it turned on because it provides important protections.

It is, however, a pain if you do a lot of installations on your computer.

Be sure to use Windows Firewall, and follow Windows recommended procedures.

A router is your best protection -- do not connect your computer directly to your Internet Service Provider.

A router connects to your Internet Service Provider with the IP address they give you, and then gives your computer a special IP address in the 192.168.x.x range.

More about this in the 1's and 0's Flying Through the Air course.

Your Internet Service Provider also does a lot to protect your computer by not allowing malicious connections.

Updates (the same concepts for Windows, MacIntosh, and Linux)

Always, always, always accept update requests originated by Microsoft, Apple, your Linux supplier, or the original publisher of your application programs. Microsoft Office updates are especially important because they have had a lot of vulnerabilities.

Never, never, never click on an "update" from anywhere else, especially one originating from an e-mail or website. They are phonys.

More about this in the 1's and 0's Flying Through the Air course.

Automatic updates are turned on by default when you install the operating system, and should be left turned on.

Don't connect a computer with an unsupported operating system (Windows XP or earlier or Mac OS Version 9 or earlier) to the Internet. You can safely use them as standalone computers.

(10 to 15 Minute Break)

Practical Tips and Techniques

When A Program Locks Up, or Whenever You Are In Doubt

Windows: Ctrl - Alt - Del

Task Manager (press Start - run and type in: taskmgr or press Ctrl - Alt - Del (all together), then click the Task Manager button.
Resource Monitor (press Start - run - and type in: resmon) or press the Resource Monitor button in Task Manager

Mac: When in doubt, press Option - Command - Escape to force quit a problem program.
Mac: To see processes and monitor activity use Finder - Go - Utilities - Activity Monitor.

Setting Up User Accounts

Windows: Start - Control Panel - [View by: Category] - User Accounts and Family Safety - Add or remove user accounts
Mac: Apple Symbol (in upper left corner of screen) - System Preferences - Accounts

Make sure you have a strong password on your administrative account.

Create a general (non-administrative) account to do your daily work

Unfortunately, this will require an extra step of logging in when you boot your computer.

Always have a strong password on your router's login. More information in the 1's and 0's Flying Through The Air course.

How Do I Protect My Computer and Data?

Windows Resources: all at Start - Control Panel - [View by: Category] - System and Security

Action Center - gives a summery of problems on your computer, and ways to fix them.

Read the recommendations carefully and follow most of them.

Windows Firewall - inspects all Internet packets attempting to enter your computer and blocks all but packets that have a good reason to be accepted.

One of the two most important protections you have from the Internet (the other is a router connected between your computer and your Internet Service Provider (ISP, such as Comcast)).

Always leave on for both Home or work (private networks), and for Public Networks.

Allow Remote Access - allows someone to take control of your computer from over the Internet.

Always have this turned off, unless you have a good reason to turn it on.
You may want to turn it on when a legitimate help desk requests it.
You may also want to turn it on if you use a remote access program such as Go To My PC.

You will probably need to adjust your router settings also if you allow remote access.

Windows Update - keeps your Windows Operating System up to date with the latest enhancements and security patches.

Always have this turned on to do automatic updates.

Backup and Restore - Window's native back up program. Let's you choose data or operating system backup or both.

Use this or another program or method of your choosing, but don't go without backups!

Make a Windows System Repair Disc - Gives you the possibility of booting your computer if your C: drive or your computer hardware completely fails and the computer will not start.

Must be burned to a blank DVD.

Only copies the files necessary to boot your computer and run repair tools. It does not contain a full copy of your operating system - see System Image Disc just below.

Start - Control Panel - [View by: Category] - Backup and Restore - Create a system repair disc

Store a System Image - a complete copy of your computer's operating system to .

May be saved on a backup hard drive (don't use the C: drive!) or a blank DVD.

Much larger than the files needed for the System Repair Disc.

Not needed if you include a System Image as part of your regular back up procedures.

Start - Control Panel - [View by: Category] - Backup and Restore - Create a system image

MacIntosh OS / X Resources:

Operating System Updates

Always done automatically on the Mac. Not as critical as Windows because Mac has very few vulnerabilities, but accept any updates that originate from the operating system.

At Apple Symbol (in upper left corner of screen) - System Preferences

Apple Store (called Software Update on earlier versions of Mac OS / X) - updates the installed software on your computer that you got from Apple.

Time Machine - creates backups of your operating system and data.

Time Machine is excellent. Use it!

Requires an external hard drive be attached to your computer and designated as the back up disk.

Only significant deficiency: No easy way to choose between backing up your operating system, your data, or both.

Security - General - password control for the entire computer, not just a specific user.

Best to keep the default settings unless you have a good reason to change them.

Security - Firewall - inspects all Internet packets attempting to enter your computer and blocks all but packets that have a good reason to be accepted.

Definitely leave this turned on and let the Mac manage the settings.

At Finder - Go - Utilities

Software Update - gives a summery of problems on your computer, and ways to fix them.

Read the recommendations carefully and follow most of them.

Time Machine - creates backups of your operating system and data.

Time Machine is excellent. Use it!

Requires an external hard drive be attached to your computer and designated as the back up disk.

Only significant deficiency: No easy way to choose between backing up your operating system, your data, or both.

Keychain Access - creates and keeps track of all your passwords, on all your Apple devices.

Generally reviewed as an excellent program.

Takes some set up before it will work.

Apple is storing and maintaining your passwords. Highly safe and secure, and always recoverable through your Apple Store account.

Windows has no equivalent program.

Questions and answers about any topic covered in the entire course

If there is time:

Inside the Operating System

Multiprocessing
Operating systems only appear to run multiple programs at the same time. They are really switching between small slices of the programs, thousands of times a second.
Process Priority.

Changing the Priority in Windows Task Manager - Processes tag.

Use 5 running instances of monopolizeCPU.exe and Windows Task Manager to see CPU usage.
Then change priorities on the fly and watch the CPU priority change:
monopolizeCPU.cpp
Note: this program will use a lot of CPU time, but even multiple copies can be run without slowing the computer using normal priorities
monopolizeCPU.exe
Illustration: Task Manager Performance tab

Memory Protection
Operating systems give each program a portion of the computers memory, and it protects other programs from accessing that memory.
Microsoft's original DOS did not have this protection. The "DOS based" versions of Windows (Windows 3.1, Windows 95, Windows 98, and Windows ME) tended to crash because of the poor memory protections.
The "NT based" versions of Windows (Windows NT, Windows 2000, XP, Vista, 7, and 8) have had increasingly good protection.
MacIntosh computer have had this protection from the beginning in 1984, and established a much better reputation because of their stability.
Unix and Linux systems have had this protection since the 1970's.
Example of a program that improperly tries to access memory outside it's assigned memory area:

crasher.cpp
Note: Careful -- this will crash and create a protection error. Recover using Task Manager (ctrl-alt-del):
crasher.exe

Virtual Memory
If the operating system needs more memory than is actually installed on the computer, it swaps back and forth from a disk drive the memory that is being used the least.
Obviously, this is not a good situation, and it slows down the computer considerably.
Although not an ideal solution, the operating system still does prevent the computer from crashing because it has run out of real installed memory.
Having enough memory installed on your computer is the single most important thing you can do to assure fast performance.
Example of a program that gobbles up all the available memory and slows down your computer.

"Thrashing" (too much swapping to disk) if the computer is overloaded with programs.
thrasher.cpp
Note: Be careful - this program will turn your computer into molasses. If it doesn't, leave it open and start up a second program.
Recover my closing the window that appears, or if that fails use Task Manager (ctrl-alt-del then Applications - thrasher.exe - End Task).
thrasher.exe

We Do Windows, Understanding Computer Operating Systems, Fall 2014, Osher Lifelong Learning Institute, University of Illinois at Urbana-Champaign