Backing up the Registry provides no inherent virus protection. Anonymizers for email and Web browsing have nothing to do with viruses. Cookies have nothing to do with viruses. Happy99 used Usenet news, as well as email. Chat has nothing to do with viruses.
Email encryption has nothing to do with viruses.
The Melissa virus was not polymorphic. Polymorphic viruses do not change their payloads. Digital signatures have little to do with viruses, and chapter nineteen does not discuss key management at all. E-commerce does not have anything to do with viruses. Y2K does not have anything to do with viruses.