Transcription: Be careful! Many FTP files contain viruses. With computers, a virus is a destructive program that attaches itself to files. When you run an infected program, the virus will affect the performance of your PC and possibly destroy data on your PC's hard disk or floppy disk. Your best protection is to purchase an antivirus program which finds and removes infected programs. Remember, an ounce of prevention is worth a pound of key. So if you plan to do a lot of downloading, invest in an antivirus program.