How to teenager-proof a Windows 7 PC

Once you're sure the PC is free of malware, create standard user accounts for each user and install an arsenal of free security programs and activity monitors to enhance the machine's virus resistance.

Dennis O'Reilly Former CNET contributor
Dennis O'Reilly began writing about workplace technology as an editor for Ziff-Davis' Computer Select, back when CDs were new-fangled, and IBM's PC XT was wowing the crowds at Comdex. He spent more than seven years running PC World's award-winning Here's How section, beginning in 2000. O'Reilly has written about everything from web search to PC security to Microsoft Excel customizations. Along with designing, building, and managing several different web sites, Dennis created the Travel Reference Library, a database of travel guidebook reviews that was converted to the web in 1996 and operated through 2000.
Dennis O'Reilly
5 min read

Families share: meals, money, space, telephones, computers, you name it. Depending on the circumstances, the sharing can be a source of joy or of conflict -- frequently it's a little of both.

If there's a computer in your household that more than one person uses, you can minimize the chances that the machine will breach the family peace by configuring the system to meet the unique needs of each user. If one or more of those users is a teenager, you owe it to all of us to help prevent malware from spreading by implementing some basic safety precautions.

A tale of two teenagers and the damage of unbridled downloads
A Mac-using friend recently asked for help with the Windows PC she bought several years ago for her husband and their two teenage children to share. She had no experience with Windows and hadn't installed any antivirus or other security software on the machine. Even worse, all four of the family members signed into a single administrator account.

As you can imagine, the machine was soon rendered nearly useless by every kind of malware known to humankind. When I started the PC, Windows Update was inaccessible, Internet Explorer's search option had been reset to the dreaded Babylon "service" (see this CNET forum post for instructions on removing Babylon from your PC), and I was unable to open popular security-software sites in either Internet Explorer or Firefox to download any antivirus programs.

After several attempts I was able to download and install both Microsoft's free Security Essentials and the free version of Malwarebytes' Anti-Malware program. Once Security Essentials' real-time virus scanner was active, I updated Malwarebytes Anti-Malware's virus-definition database and then ran a full scan with the program.

The first Anti-Malware scan uncovered more than 90 suspicious objects. I removed the items, rebooted, and did another full scan with the program. The second scan caught more than 20 potentially dangerous objects, and the third scan only a handful. After four full scans and system restarts, the PC came up clean.

Malwarebytes Anti-Malware scan results
After four full scans by Malwarebytes' free Anti-Malware program the infected Windows 7 PC was finally fully disinfected. screenshot by Dennis O'Reilly/CNET

I convinced the PC's owner to spring for an upgrade from Windows Vista to Windows 7. After the OS upgrade, I made sure Windows and Microsoft Security Essentials were set to update automatically and all other built-in security features were active and up-to-date.

Next, I downloaded and installed the latest version of Firefox and several security add-ons for the browser: NoScript, HTTPS Everywhere, Web of Trust, Ghostery, Better Privacy, and AdBlock Plus. All six of the add-ons are free for non-commercial use.

(See the related stories listed above for more on these and other Firefox security add-ons.)

Restrict everyone's use of Windows administrator accounts
There's a simple way to reduce the chances of a computer infection: make sure everyone signs into their own standard Windows account. Standard accounts are no-brainers for children, but they make sense for grown-ups, too.

About the only times you need administrator privileges are when you want to download a program or change a system setting. Not many of us are likely to do either in the course of a typical workday. On those rare occasions when you need an administrator privilege, just right-click the restricted file, program, or setting, choose "Run as administrator," and enter an administrator name and password.

To create a standard user account, press the Windows key, type user accounts, press Enter, click "Manage user accounts," and choose "Create a new account."

Windows 7 User Accounts dialog
Minimize the risk of a computer infection by using a standard Windows account via Win7's User Accounts applet. screenshot by Dennis O'Reilly/CNET

Give the account a name and press Enter. To password-protect the account, select it in the Manage Accounts window, click "Create a password," enter the password twice, and press Enter.

Control users' Web viewing, other activities
Parents know they need to monitor their children's online activities. Microsoft's free Windows Live Family Safety service lets you receive reports of a Windows user's activities and restrict the account in various ways, including five levels of Web content filtering.

After you visit the Windows Live Essentials page to download the program, make sure to click "Choose the programs you want to install" rather than the default option that installs 11 separate apps.

Windows Live Essentials installation options
Select the second of the two options offered by the Windows Live Essentials installer to avoid getting more software than you bargained for. Screenshot by Dennis O'Reilly/CNET

On the next screen of the installer, uncheck the programs you don't want and click Install.

Windows Live Essentials program-selection window
Uncheck the Live Essentials apps you don't want and click Install to get started with the Family Safety program. Screenshot by Dennis O'Reilly/CNET

To set up monitoring of a Windows account, choose Windows Live Family Safety under Windows Live on the Start menu (or press the Windows key, type Windows Live Family Safety, and press Enter). Click "Add or manage family members on this computer," and select the account you want to monitor.

Windows Live Family Safety account-monitor wizard
Check the Windows account you want to monitor via Family Safety and choose Next. Screenshot by Dennis O'Reilly/CNET

Use the drop-down menu to select the Hotmail account that will receive the monitoring reports and click Save. To change the monitoring settings, visit the Family Safety site and click Edit Settings under the account name.

The monitoring options are listed in eight categories in the left pane; click one or choose its link in the main window to open the settings in that category.

Windows Live Family Safety account-monitoring options
Eight categories of monitoring options are offered by the Family Safety app. Screenshot by Dennis O'Reilly/CNET

In addition to restricting the hours of the day and days of the week the user may access to the computer, you can limit gameplay and block all or certain applications. The five levels of Web filtering offer a manual white list of approved sites, child-friendly sites only, general (no adult sites), online communication (no adult sites), and "Warning on adult" that does no blocking but pops up an "Are you sure?" window. You can also block the person's ability to download files from the Internet.

Windows Live Family Safety Web-filtering options
The Family Safety monitor lets you select one of five levels of Web filtering: from a simple list of approved sites to warn but don't filter (and three adult-blocking settings in between). screenshot by Dennis O'Reilly/CNET

By default Family Safety sends a weekly activity report for the monitored account. You can view the account activity over a longer period of time by choosing a date range under the "Web activity" and "PC activity" tabs of the activity-report settings. The report includes Web pages visited, the number of visits to each page, their activity on the page, and the date the page was last visited.

The time and date of each account session is shown under PC activity, along with the applications the person used, the files the account downloaded, and the games played.

Even if this level of scrutiny of your children gives you pause, consider the deterrent effect of your teenagers knowing you're looking over their shoulder, whether you're actually in the room with them or not. It's also a way to make sure your kids aren't on Facebook or YouTube when they're supposed to be doing their homework.

There's no substitute for giving your children your undivided attention as often as possible. When direct interaction with your kids isn't possible, keeping a close watch over their Web activities and computer use can help keep them pointed in the right direction.