IT guide

PC security and viruses

How to protect your PC from viruses and malicious software.

Contents
Steps to protect your PC

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Step 1: Install anti-virus software

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Step 2: Install adware and spyware protection

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Step 3: Essential security settings on your PC

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Step 4: Update your computer

If you suspect your PC is infected

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Scan your computer

Virus removal advice

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Disabling and enabling System Restore

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Adware or spyware removal

Help

August 2010

www.kent.ac.uk/itservices
Information Services

IT Guide: PC security and viruses

Steps to protect your PC

You must protect your PC before connecting to the Kent network by following the steps below.
If your PC infects the network, your Kent IT account and/or connection may be disabled.

Step 1: Install anti-virus software

Windows users: never try to install more than one anti-virus program as this causes serious technical
problems. The University recommends Microsoft Security Essentials which is free to install. You need to
install this if:
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you have a Windows PC and do not already have up-to-date anti-virus software on it

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the software you have has expired: if your software has expired then you are no longer receiving regular
anti-virus updates. You need to remove your old software so that you can install Microsoft Security
Essentials (see Checking and removing software section opposite).

If you use the study bedroom network and do not use one of the programs listed below, you will need to
make an appointment with the Study Bedroom Helpdesk to get your alternative program approved:
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Avast! Anti-virus

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Microsoft Security Essentials

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AVG Anti-virus

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Norton 360

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Avira Antivir

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Norton Anti-virus

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ESET NOD32

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Norton Internet Security

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F-Secure Anti-virus for Workstations

or F-Secure Client Security

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Panda Anti-virus

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Sophos Anti-virus

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Kaspersky Anti-virus/Internet Security

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Symantec Anti-virus

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McAfee Anti-virus

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Trend Micro Anti-virus/Internet Security

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Microsoft Windows Live Onecare

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Webroot Anti-virus

Mac users: you are required to install anti-virus software before connecting your computer to the Kent
network. Check the Apple website for recommendations, or install iAntivirus (Mac OS X 10.5 and 10.6) or
ClamXav (Mac OS X 10.4 and 10.5): see page 3.

How to install Microsoft Security Essentials

Windows users
Do not install Microsoft Security Essentials if you have any other anti-virus program installed on your machine.
Running two anti-virus programs causes serious technical problems.
1. Download Microsoft Security Essentials from the web page below or install it from a Health Check DVD
available from IS help points (see Help section on the back page):
www.microsoft.com/security_essentials
2. Follow the on-screen instructions as advised below:
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if using the DVD, select Anti-Virus tools (from the top menu) then select Install Microsoft Security
Essentials

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if downloading from the web, click the Download Now button and select your language and
operating system. Click Run or Open when prompted (if you are using Firefox, choose to save the
file to the desktop, then double-click the file on the desktop to run it).

3. Follow the on-screen instructions to complete the installation process. You should now run a full antivirus scan: open Microsoft Security Essentials and select the appropriate option.
Microsoft Security Essentials runs in the background protecting your PC: it should regularly update itself
automatically.

IT Services website: www.kent.ac.uk/itservices

IT Guide: PC security and viruses

How to install iAntivirus or ClamXav

Mac users
Install either one from a Health Check DVD available at IS help points (details on back page), or download
from:
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iAntivirus: http://iantivirus.com (Mac OS X 10.5 or 10.4)

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ClamXav: http://clamxav.com (Mac OS X 10.4 or 10.5).

Advice on starting the Health Check DVD

Windows users
To use the DVD, insert it into the PCs DVD drive. If a menu does not automatically appear:
1. Click on My Computer (or Computer in Vista and Windows 7) from the desktop or the Start menu.
2. Double-click on the DVD drive which contains the Health Check DVD. If the menu fails to appear,
double-click on the index.html file in the www folder.

Mac users
Double-click on the DVD drive icon, and double-click on the index.html file in the www folder.

Checking and removing software

Windows users
1. Follow the instruction for your operating system:
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Windows 7: Click on Start, Control Panel, Uninstall a Program or Programs and Features

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Windows Vista: Click on Start, Control Panel, Programs and Features

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Windows XP: Click on Start, Control Panel, Add or Remove Programs.

2. You will see a list of programs on your PC: check for Norton, McAfee or any other anti-virus programs.
3. To remove a program (for example, if your subscription for updates has expired or if you plan to use
the study bedroom network and do not have an approved program):
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Windows 7: select the program and click the Uninstall button at the top of the list

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Windows Vista or XP: click the Remove button next to the program in the list.

Mac users
1. Using Finder, locate the program you want to remove. Programs are usually located in the Applications
folder.
2. Click on the program and drag it to the Trash can on the dock to remove it.

Help and support: helpdesk@kent.ac.uk

IT Guide: PC security and viruses

Step 2: Install adware and spyware protection

As well as viruses, your PC is at risk from adware (programs that cause intrusive advertising to pop up on your
PC) and spyware (programs that may access your personal data and could control your PC for financial gain).

If I have anti-virus software do I need anything more?

We recommend that you install Malwarebytes, a free adware and spyware removal tool. This adds an extra
layer of protection, and can be used to help you remove malicious software if your PC gets infected.
Download Malwarebytes from the web (or install it from the Health Check DVD, see back cover for details):
www.kent.ac.uk/itservices/secure/adware.html

Step 3: Essential security settings on your PC

Set passwords on user accounts
Password protecting user accounts helps prevent malicious software accessing your data.

Windows 7, Vista or XP: all user accounts

Click the Start button, then Control Panel and select User Accounts (or similar), and follow on-screen
instructions to set a password (you can also click Help in the top menu for further advice if unsure).

Windows XP: administrator account

1. Click the Start button, then select Run. Type control userpasswords2 in the box and click OK.
2. Select the Administrator username, click Reset Password and enter a new password.
3. Ensure the Users must enter a username and password to use this computer box is ticked. Click OK.

Mac OS X
1. Click the Apple menu, System Preferences, Accounts (in the System section).
2. Click on an account name to select it; click the Change Password/Password Reset button:
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if asked for your old password enter your current password in the box

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enter a new password in the New Password box, verify it below, and click
Change Password/Password Reset.

3. Repeat step 2 for each account you need to set a password on.
4. Click the red cross (left-hand corner of the window) to save changes and then close the window.

Disable the guest account

Guest accounts are disabled by default in Windows Vista and Windows 7. Not applicable for Mac users.

Windows XP
1. Click the Start button, then select Control Panel (if you cant see it, try Settings then Control Panel).
2. Click User Accounts. In the User Accounts window click Guest. Click Turn off the guest account.

Mac OS X
1. Click the Apple menu, select System Preferences, Accounts (icon).
2. Select the Guest account in the left-hand list. If you cant select the Guest account then click on the
padlock at the bottom of the window to enable changes to be made.
3. Untick all boxes to disable Guest account access.
4. If you clicked the padlock to enable changes, click it again to disable changes.
IT Services website: www.kent.ac.uk/itservices

IT Guide: PC security and viruses

Turn off file sharing

File sharing leaves your computer open to malicious attacks. Attackers can gain complete read/write access
to your computer, so you should disable file sharing if you do not absolutely need it.

Windows 7
1. Click the Start button, then select Control Panel, Network and Internet, Network and Sharing
Center.
2. Click the Change Advanced Sharing Settings from the left-hand pane.
3. Under Home or Work section, select Turn off File and Printer Sharing and Turn off Public Folder
Sharing. Do the same under the Public section.
4. Click the Save Changes button at the bottom of the page, then close all windows to finish.

Windows Vista
1. Click the Start button, then select Network, Network and Sharing Center.
2. Click the arrow at the end of the row that says File sharing to expand it.
3. Select Turn off file sharing and click Apply.
4. Do the same for Public folder sharing and Media sharing, then close all windows to finish.

Windows XP
1. Click the Start button, then select Run. In the Open box type fsmgmt.msc and click OK.
2. Click the Shares folder (left-hand window). A full list of shares appears in the right-hand window.
3. Right-click on all shares that do not have a $ symbol after them, select Stop Sharing, Yes to confirm.
Shares with a $ symbol are safe and are required by the operating system to function fully.
4. To finish, click File, Exit (from the top menu).

Mac OS X
1. Click the Apple menu, select System Preferences, Sharing (icon).
2. Untick the box next to File Sharing in the list of services on the left.
3. Click the red cross (left-hand corner of the window) to save changes and close the window.

Step 4: Update your computer

Operating system updates
Regularly check and install system updates to help prevent malicious software from accessing your data:
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Windows: www.windowsupdate.com

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Mac: www.apple.com/softwareupdate

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Other operating systems: refer to the online help or documentation for the system you are using.

Improve the security of Internet Explorer (versions 7 and 8)

1. Click Tools, Internet Options, and select the Security tab.
2. Select the Internet zone at the top of the dialog box.
3. Set security level to Medium-high using the slider (if not visible, click Default level). Click OK.
If you have an earlier version of Internet Explorer we recommend that you upgrade to the latest version from:
http://www.microsoft.com/windows/downloads/ie

Help and support: helpdesk@kent.ac.uk

IT Guide: PC security and viruses

If you suspect your PC is infected

Scan your computer
Use Microsoft Security Essentials to scan your Windows PC
1. Click Start, All Programs, Microsoft Security Essentials.
2. Under Scan options select Full.
3. Click Scan now
For more help on scanning your computer and disinfecting viruses, see the Microsoft Security Essentials help:
click the help icon in the top right of the Microsoft Security Essentials window.

Use iAntivirus to scan your Mac

1. iAntiVirus is set to automatically start whenever you begin using your Mac. If during your session you
decide to exit iAntiVirus, you may start it again by clicking the iAntiVirus icon in the Applications,
iAntiVirus folder.
2. Once the program has loaded, select the button that says Scan my Mac.
3. In the next window select Normal Scan and click Start Scan. The scanning window appears
showing progress of the scan.

Virus removal advice

If your anti-virus software detects a virus, you may be offered an option to remove or delete the virus. Be
aware that removing or deleting the virus may render your computer inoperable if it is attached to a system file,
choose this option with caution.
Some viruses cannot be removed. If you find this happens, try disabling system restore and run the scan
again.

Disabling and enabling System Restore

Windows 7 or Vista users
1. Click the Start button, then select Control Panel, System (Vista users, click System and
Maintenance, then System).
2. Select System Protection from the left pane.
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Windows 7 users: ensure the System Protection tab is highlighted and click the Configure button.
Then select the option under Restore Settings to Turn off system protection and click OK. Click
yes to confirm and then click OK (this will delete all previous restore points).

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Windows Vista users: to turn off System Protection for a hard disk, clear the check box next to the
disk, and then click OK. Then click Turn system Restore Off to confirm and click OK (this will
delete all previous restore points).

3. Run a virus scan by opening your anti-virus software and following the instructions on screen.

IT Services website: www.kent.ac.uk/itservices

IT Guide: PC security and viruses

4. When the scan is complete and any virues have been removed, you can enable system restore again:
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Windows 7 users:
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Click Start, Control Panel, System.

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Select System Protection from the left pane.

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Ensure the System Protection tab is highlighted and click the Configure button.

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Select the option under Restore Settings to Restore system settings and previous versions of
files and click OK

Windows Vista users:

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Click the Start button, then select Control Panel, System and Maintenance, then click System.

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Select System Protection from the left pane.

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To turn on System Protection for a hard disk select the check box next to the disk and click OK.

Windows XP users
1. Click the Start button, then select All Programs, Accessories, System Tools, System Restore,
System Restore Settings.
2. To disable System Restore, Tick the Turn off System Restore box then click Apply. Click Yes to confirm
then OK. You will be prompted to reboot your PC.
3. Immediately after logging back in to your PC, run a virus scan by opening your anti-virus software and
following the instructions on screen.
4. When the scan is complete and any viruses have been removed, you can enable system restore again:
Start, All Programs, Accessories, System Tools, System Restore, System Restore Settings.
5. Untick the Turn off System Restore box, then click Apply, OK.

Adware or spyware removal

If you have installed Malwarebytes software as advised on page 4, you can use it to detect and remove any
malware (adware or spyware) programs that are causing you problems. Open Malwarebytes on your computer
and run a scan, following on-screen instructions to remove any detected software.

Help and support: helpdesk@kent.ac.uk

IT Guide: PC security and viruses

Help
Information Services help points
Canterbury
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IT & Library Support Desk, Level 2 Centre, Templeman Library

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Welcome Desk, Level 1 Centre, Templeman Library

Medway
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IT Helpdesk, Drill Hall Library

Tonbridge
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Service desk, Tonbridge Library

Telephone, email and online help

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Email: helpdesk@kent.ac.uk

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Phone: Students (01227 82) 4999; Staff (01227 82) 4888

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Kent IT user guides: www.kent.ac.uk/itservices/help/guides

Health Check DVD and user guides

A Health Check DVD and copies of all Kent IT user guides are available from the Information Services help
points listed above. Alternatively, you can read this advice and download the software from:
www.kent.ac.uk/itservices/secure

IT Services website: www.kent.ac.uk/itservices