They probably already know... (Score 1)

Just have your students surf on the computers without A/V for about 15-20 minutes, guaranteed that they will all be infected. Then just do a little research and have them run some malware removal programs, have them go through the registry and see if they can find the specific keys that they were told the viruses created when they were doing the research on what they had become infected with. Most of the students are probably experienced with viruses and that most of them are really just programs that stupid people install.