Removing a Virus (Windows)

If your computer has been infected by a virus, ITS recommends that you print out and follow the guidelines below. Section A will help you to identify the current level of security on your computer and the files you will need to download. Section B will help you install and run the antivirus program.

New viruses are released every day. It may take time for the vendor of your antivirus software to develop a solution for a new virus. For these reasons, we cannot guarantee that the steps below will successfully remove all the viruses from your computer.

Section A: Evaluate Security and Download Files

1. Operating System Patches

Windows regularly releases security patches to correct security vulnerabilities. Start by making sure that you have all released security patches for your operating system.

• If you currently have an Internet connection, you can download the necessary Windows security updates from http://windowsupdate.microsoft.com using Internet Explorer (IE). You may need to visit the site several times in order to download all of the necessary updates.
• If you do not have an Internet connection, or ITS has blocked your computer because of a virus, you will need to download the updates on another computer, then transfer them to and install them on the infected computer.

2. Antivirus Software

Check to see if your computer has an antivirus program installed. If you do not have an antivirus program installed, or if updates are not available for your virus definitions, you should download the Symantec Antivirus program from the ITS software download page.

3. Virus Definitions

Each antivirus program has its own method of checking for virus definition dates. If you receive a message that your subscription has expired, you will need to either renew your subscription or install new antivirus software.

To update Symantec's virus definitions, visit Symantec's virus definitions page.

To check to see if you have the latest virus definitions for Symantec Antivirus, follow the steps below:

1. From the Start menu, click All Programs.
2. Select Symantec Client Security and click Symantec Antivirus.
3. The Virus Definitions file is located in the bottom right-hand corner. The version listed reflects the date of the last update.



4. Symantec AntiVirus updates virus definitions at least twice a week. If you have a version that is more than 2 days old, ITS recommends that you update the virus definitions for your computer.

Section B: Install and Run Necessary Software

1. Install Downloaded Software

Install the software that you downloaded in Section A. Make sure to install the antivirus software before installing or updating the virus definitions.

2. Restart the Computer in Safe Mode

Windows has an operating state called Safe Mode, which disables devices and loads as few executable modules as possible. A virus can be most easily be detected in this mode. Click one of the links below for instructions on restarting your computer in Safe Mode:

• Windows Vista in Safe Mode
• Windows XP in Safe Mode

3. Scan for Viruses

If you do not see the Symantec shield in the systray next to the clock while in Safe Mode, start Symantec manually by following the steps below:

1. Click Start and select All Programs.
2. Select Symantec Client Security and click Symantec Antivirus.
3. Under the Scan Selection, click Scan Computer.
4. Select the drives you want to scan and click the Scan button.
   Note: The length of the scan will vary from a few minutes to more than an hour, depending on how fast your computer is and how many files you have. If the antivirus program finds a virus, you should follow the prompts to quarantine, clean, or delete the infected file.
5. Restart the computer.

Getting Help

For questions, or if the virus persists, call the ITS Customer Support Center at 213-740-5555 or send an email to consult@usc.edu.

Last updated: Monday, October 19, 2009, 11:42AM PDT