You are a desktop support technician for your company. All client computers run Windows XP Professional.
A user reports that she is receiving e-mail messages stating that she sent a virus. The user works at home and has a broadband connection to the Internet.

You discovered that the user purchased an antivirus application and installed it on her computer. She ran the virus scanner on her computer, but it did not detect a virus. She continues to receive e-mail messages stating that she sent a virus.

You need to identify the cause of these e-mail messages. You instruct the user to log on as an administrator.

What should you instruct the user to do before running the virus scanner again?

A.
Download the most recent virus signature file.

B.
Run Network Diagnostics to scan her computer.

C.
Connect to the Microsoft Windows Update Web site and scan her computer.

D.
Run the Microsoft Baseline Security Analyzer (MBSA) tool and scan for Windows vulnerabilities.