Since the appearance of MP3's, there has been a whole lot of sharing going on. Sharing files can be good and bad. It can be good to save time, or to access your files from a lab, but bad if you get infected with a virus. You may not even know you have one. Viruses spread like wildfire in the residence halls.
Email is the most common methods of infection.
Another method of infection is downloading games, sharing files with friends or playing MP3's on other peoples computers. An alarming number of them didn't know they have to update their virus protection. Many have been using the original program that came with their computer 2 years ago. At this point it is necessary to visit the room and try to remove the virus. Some are very easy to remove, and some take a person that knows what they are doing.