COMPSEC

Dr. Gerry Santoro – Founding Associate Professor

Module 8 – Operating System Installation and Restoration

Introduction

If you adopt all of the protection strategies covered so far, you are unlikely to encounter any problems with computer security. However, good security strategy advises that you be prepared for contingencies. One contingency is when a computer becomes infected with malware that cannot be removed. In a situation like this, the only resolution is to completely wipe the operating system and all application and data files and reinstall the OS and applications.

Important Note: The methods in this topic may be beyond the technical ability of the student. Although many of my students in the College of Information Sciences and Technology have installed or reinstalled operating systems, many have not. This module is included for completeness; however I caution that you should NOT attempt this unless you feel certain of your skills.

This is similar to me working on an automobile. Although I feel comfortable reinstalling an operating system on a computer, I would NOT feel comfortable working on the transmission of my truck. I do not have the correct tools, or the correct experience, so I take my truck to a trusted mechanic.

In the same way, there are many computer repair shops that would be more than happy to reinstall your operating system, or install a new operating system, for a fee.

Why Would You Want To Do This?

There are a number of scenarios in which you might want to either install a new operating system or reinstall your current operating system:

  1. Your computer has been infected with malware that cannot be removed.
  2. You have purchased a used computer and want to be sure it is wiped clean before you re-purpose it.
  3. You want to upgrade to a newer version of your operating system.
  4. Your computer has started running very slowly, so you want to effectively give it a “tune-up.”
  5. You want to gain experience with a free version of Linux.

In all of the above cases, you will want to be sure that you have backups of your data files on other media and the original disks or URLs for downloading your applications (as well as any license codes that may be required). In some cases, installing or reinstalling an operating system may require formatting the hard drive, which will erase everything that is stored there. You also need to be sure that you have either the installation CD/DVDs (or other media) for the operating system you wish to install or the URL for the new OS version installation.

Installing, or reinstalling, an operating system is scary and complex the first time you do it. After that it becomes easier. There are many versions of Linux, such as Debian, Red Hat, Umbutu, etc. Some people periodically switch between the versions to learn about the nuances and different uses for each. Please be aware that other operating systems, such as those from Microsoft and Apple, are subject to licensing. Be sure that you have a current license for every installation.

Reinstallation versus Restoration

Users are sometimes confused by the system restoration capabilities that some operating systems (such as Windows XP, Vista, or 7) provide. This is not the same thing as reinstalling the operating system. The Windows System Restore function is intended to help recover from problems with a device driver, a missing or corrupt DLL, or an issue with the Windows Registry. When software is installed, Windows will create a “restore point” with information to allow the OS to be restored to its configuration at that point in time. Please note that this will NOT restore deleted or corrupted data files—only system information will be restored.

Occasionally, a new piece of hardware (and driver) or application is installed and this results in problems. In this situation, if the uninstall function does not remove the problem, the system restore function may be the solution.

Please consult your Windows documentation for information regarding the System Restore tool. It is a powerful and easy-to-use tool, but advance knowledge is important. Again, unless you are sure what you are doing, you are better off paying for specialized computer support. Be sure your data files are backed up on removable media!

OS Installation and Reinstallation Process

The specific process for operating system installation/reinstallation varies with different operating systems and different brands of computer. In some cases, you will need installation media, such as an installation CD or DVD. In other cases, a set of installation files are located on a read-only portion of the primary hard drive (often called a recovery image). In yet other cases, the recovery image is merely a starting point, with the rest of the OS downloaded from the Internet. In these latter cases (such as reinstallation of Mac OSX Mountain Lion) it is important to have a working Wi-Fi connection.

Some computer brands encourage you to create a recovery CD while your computer is working correctly. You can then use that CD to initiate recovery or OS reinstallation if it later becomes necessary. Be sure that you read the User’s Manual for your computer when you acquire it. If you acquire a computer but do not have the manual you can usually find the manual on the vendor’s Web site.

Having done this many times, I always recommend the following:

·  Have another computer available and connected to the Internet. I typically use a laptop. This allows me to consult the directions for installation or reinstallation while I am doing the work. If I encounter any problems I can use the second computer to gather more information. I may also use it to download additional drivers as necessary.

·  Go to the web site for your specific model of computer. Different vendors have different methods for OS installation and reinstallation. For example, I am typing this on a Hewlett-Packard Pavilion p7-1414 desktop computer. Support information for this computer, including drivers and OS recovery, are located online at http://h10025.www1.hp.com/ewfrf/wc/product?cc=us&lc=en&dlc=en&product=5297006

·  Review all steps before you begin! This will ensure that you have everything you need before you start the process or installation or reinstallation.

Some Examples

Here are a few examples to illustrate the various processes. Remember, the specific process varies by OS version and computer model and vendor. These examples are only for illustration – if you actually need to do these please consult more detailed instructions online (as noted above).

How to install or reinstall Mac OS X Mountain Lion

(Excerpted from OS X Mountain Lion for Dummies http://www.dummies.com/how-to/content/how-to-install-or-reinstall-mac-os-x-mountain-lion.html)

Be sure you are connected to the Internet before you start this!

  1. Boot from your recovery HD partition by restarting the Mac while holding down the CMD+R keys
  2. Select ‘reinstall OS X’ and click continue
  3. You will see a screen informing you that your computer’s eligibility needs to be verified – click continue.
  4. The Mountain Lion splash screen appears. Click continue.
  5. The Mountain Lion software license agreement appears. Read it and click agree.
  6. Select the disk upon which you want Mountain Lion installed.
  7. Enter your Apple user id and password.
  8. Wait 30-60 minutes.
  9. If this is a new installation you will have to enter setup information.

How to Clean Install Windows 7

From About.com PC Support ( http://pcsupport.about.com/od/operatingsystems/ss/windows-7-clean-install-part-1.htm)

  1. Backup all data files, be sure you have application and driver installation files or locations for them.
  2. Backup and copy your Windows 7 product key – if this is a reinstallation and you cannot locate your product key you can either download a free utility to gather the product key from the Windows 7 Registry, request a replacement key from Microsoft, or purchase a new copy of Windows 7. The key will look something like xxxxx-xxxxx-xxxxx-xxxxx-xxxxx- five sets of five letters and numbers.
  3. Locate your Windows 7 installation media. This could be a CD, DVD, or ISO image on a USB drive. When Windows 7 is purchased, both ISO and DVD options are available. Choose the appropriate one. If you are purchasing the computer from another person be sure to get this media. The DVD files may be copied to a flash drive if you do not have a DVD drive. The ISO file should be burned to a CD or DVD.
  4. Boot your computer from the drive with the installation media. You may need to access the BIOS for your computer to prevent it from simply booting from the hard drive. The Web documentation for your model of computer will explain how to do this – it is often as easy as holding down a key (such as F1) while the computer boots.
  5. Now you wait for Windows 7 installation files to load into memory
  6. Choose some settings – time, currency format and language
  7. Select ‘Install Now’ (note: do NOT select ‘repair your computer’ as this has a different purpose)
  8. Wait for setup to begin
  9. Read the software license and agree.
  10. When given the choice of ‘upgrade’ or ‘custom’ select ‘custom.’
  11. When available partitions are displayed – select ‘drive options (advanced)’
  12. Delete any operating related partitions. Be careful not to delete other partitions which may contain backups or data. Everything on the deleted partition will be permanently lost! You will be asked to confirm each deletion. This cannot be undone!
  13. Select the partition where you want Windows 7 installed. Then wait as the files are installed and services are started. When completed, your computer will be restarted automatically. (Be sure you have removed the installation media.)
  14. You will see a screen informing you that Windows is preparing your computer for first use. Various system checks will be performed.
  15. You will now enter a computer name and a password.
  16. Enter the product key that you saved before starting the installation. This is to ensure that you have a legal version of Windows 7.
  17. Configure security settings – I recommend the option ‘Install important updates only.’ This will ensure that security-related updates are installed automatically.
  18. You will be alerted if there are any important updates needed, in which case allow Windows to download and install them.
  19. Select other options and set up a least-privilege account for each computer user.
  20. Now log out of the administrator account, log into the least-privilege user account, and start reinstalling applications. In my case all applications come from Web locations, I only need a few product keys. You will need the administrator account password to do this.

Sidebar for small businesses

The IT support for a small business will need to know how to install and reinstall operating systems and applications. You will want to be sure that you have correct license information where appropriate. It is common to reformat the drives of computers and reinstall the OS and applications any time the computer is being re-purposed (for example transferred from one employee to another). This is often easier, and less risky, than trying to otherwise ascertain that the computer is free of malware or sensitive data.

Many companies adopt a policy stating that only certain, approved, software may be installed on company computers. Many companies also do not give the administrator password for the computer to the user, thereby preventing them from installing applications or making system changes that could compromise security. It is common for a company to have a set of system configurations (operating system and applications) that are common for various company roles (sales, accounting, administrative, etc.). This greatly simplifies the process of wiping and reinstalling the OS and applications as needed.

Resources

·  How do I use the Windows System Restore Utility? - http://pcsupport.about.com/od/toolsofthetrade/f/windows-system-restore.htm

·  How to use System Restore in Windows Vista - http://pcsupport.about.com/od/fixtheproblem/ht/system-restore-vista.htm

·  Installing and Reinstalling Windows Vista - http://windows.microsoft.com/en-us/windows-vista/installing-and-reinstalling-windows-vista

·  HP Support – Troubleshooting System Recovery Problems (Windows 8) - http://h10025.www1.hp.com/ewfrf/wc/document?docname=c03483233&cc=us&dlc=en&lc=en&product=5297006&tmp_track_link=ot_search#N1626

·  About.com – How to Clean Install Windows 7 - http://pcsupport.about.com/od/operatingsystems/ss/windows-7-clean-install-part-1.htm

·  Installing and Reinstalling Windows 7 - http://windows.microsoft.com/en-us/windows7/installing-and-reinstalling-windows-7

·  Reinstalling Mac OS X - http://www.dartmouth.edu/comp/soft-comp/software/os-support/reinstall-mac.html

·  How to Install (or reinstall) Mac OS X Mountain Lion - http://www.dummies.com/how-to/content/how-to-install-or-reinstall-mac-os-x-mountain-lion.html

·  How to Burn an ISO File - http://pcsupport.about.com/od/toolsofthetrade/ht/burnisofile.htm

·  How to Reinstall Mac OS X (Leopard and earlier) - http://www.wikihow.com/Reinstall-Mac-OS-X-(Leopard-and-Earlier)

·  How to Reinstall Windows XP without the CD - http://www.wikihow.com/Reinstall-Windows-XP-Without-the-CD

·  How to Uninstall Windows XP and Revert to a Previous Operating System - http://www.wikihow.com/Uninstall-Windows-XP-and-Revert-to-a-Previous-Operating-System

·  Installing Windows XP - http://windows.microsoft.com/en-us/windows-xp/help/setup/install-windows-xp

·  Installing and reinstalling Linux on your desktop - http://www.sutor.com/c/2010/07/installing-and-reinstalling-linux-on-your-desktop/

·  The Linux Installation HOW TO - http://www.tldp.org/HOWTO/Installation-HOWTO/

·  Why I keep reinstalling Linux - http://www.linuxjournal.com/node/1006097