Bad tech support: When in doubt, blame a virus
We talk a lot about viruses on the show and here on the site, but in reality, viruses make up a very small portion of day-to-day computer problems. In fact, many (if not most) problems that people blame on viruses are not actually viruses at all.
Many of today's computers contain at least 100,000 smaller files. These thousands of little files work together by linking and sharing jobs with each other. Viruses work by getting into that mix and confusing the files.
However, even without viruses at play, these files can get confused all on their own. In many ways a computer is like a living organism. Just as DNA, cells, the processes of life can get mixed up an mutated, the files and programs that make a computer work can also get corrupted.