Final answer:
First, verify the authenticity of the email about the malicious code threat; do not delete any files, as it could be a scareware or hoax. Use trusted resources to check for threats.
Step-by-step explanation:
In response to a message about a new malicious code threat suggesting the deletion of files from the \Windows\System32 folder, the first action you should take is to verify the authenticity of this message. Do not delete any files as this can potentially harm your system if the information is not from a reliable source. Often, such emails are a form of scareware or hoax designed to trick users into taking harmful actions on their computers. Instead, consult reputable security websites, contact your IT department if you're part of an organization, or use trusted antivirus software to scan your system for any threats.