Home
Home Students Faculty and Staff IT Security Community
left navigation bottom border

Three Security Essentials for Your Home PC(s)

While there are many things that can be done to improve the security of home computers and networks, most security experts agree that regardless of the operating system you use (Macintosh, Windows or Linux), the following three techniques are fundamental:

  • Keep software up-to-date
  • Use a host-based firewall
  • Install anti-virus software
Just as you would secure a house by locking the front door and all of your windows and installing a security system, it is critical to take a multi-layered approach to computer security. Threats seek entry through many access points, especially if you connect to the Internet, which is like a big unsafe neighborhood. The following steps detail how to put security measures in place for a Windows-based PC with connectivity to the Internet. 

Before You Proceed:

Make sure you have Microsoft Windows XP Service Pack 2 (SP2) installed. Running SP2 is one of the most important security measures you can take. Furthermore, these instructions may not work unless you are running SP2. Also, please note that these instructions are aimed specifically at students, faculty and staff members at the University of Michigan, who are all covered by the University’s anti-virus software license.

Requirement 1: Keep Software Up-To-Date

Enable Automatic Updates

The best way to keep your system up-to-date is to let Windows do it automatically through Automatic Updates. To enable this:

  1. Click Start and select Settings > Control Panel.
  2. In the Control Panel window, double-click Automatic Updates. The Automatic Updates window displays.
  3. In the Control Panel window, double-click Automatic Updates


  4. Turn on the Automatic (recommended) button.
  5. Automatic updates window

  6. Select Every Day from the drop-down menu to automatically download and install recommended updates. Click OK.

Use Microsoft Update instead of Windows Update

An important complementary aspect of enabling automatic updates is to configure it to use MicrosoftUpdate instead of Windows Update. This allows automatic updates to download critical updates for applications that run on Windows, such as Microsoft Office. Windows Update only updates the operating system while Microsoft Update updates both the operating system and Microsoft applications. Microsoft Update does not, however, update non-Microsoft applications.

To enable Microsoft Update:

  1. Launch Internet Explorer.
  2. Go to http://update.microsoft.com/microsoftupdate.
  3. Click Start Now and follow the instructions.
Note:  If you see an “Express” and a “Custom” button instead of a “Start Now” button, then your machine is already configured to use Microsoft Update instead of Windows Update.

Requirement 2: Use a Host-Based Firewall

A host-based firewall is a firewall that is running on the computer itself. This is in contrast to an external firewall that may exist on your network between your machine and the Internet.
To use the built-in Windows Firewall:

  1. Click Start and select Settings > Control Panel.
  2. In the Control Panel window, double-click Windows Firewall.
  3. In the Control Panel window, double-click Windows Firewall

  4. If prompted, click Yes to start the Windows Firewall/Internet Connection Sharing Service.
  5. Turn on the On (recommended) button, and  click OK:

Windows Firewall Window

Example of Your Firewall Working

After enabling the firewall, if you run a program such as instant messaging or a multi-player network game that needs to accept information from the Internet, the firewall may ask if you want to block or unblock (allow) the connection.

For example, here is a pop-up that results from launching AOL Instant Messenger:

a pop-up that results from launching AOL Instant Messenger

If you choose to unblock the connection, Windows Firewall will create an exception or “hole” within the firewall so that the pop-up does not occur every time that program is run. Having too many holes in your firewall is detrimental. To learn more about managing firewall exceptions in Windows Firewall, go to the Microsoft web site and search for information about "Windows Firewall" and "managing firewall exceptions."

Requirement 3: Install Anti-Virus Software

One of the most important ways you can protect your computer is to use anti-virus software. We strongly recommend that you download and install anti-virus protection, such as Microsoft Security Essentials, which is free for Windows users.

For anti-virus information at the University of Michigan, visit safecomputing.umich.edu/antivirus/.

Congratulations! By taking the steps listed above, you have just improved the security of your Windows-based PC.