Most of us know what viruses, worms, Trojan horse, and Spywares can do to our computer, to give you brief information viruses can destroy your data files, usually the system files and you can't boot your computer. Worms can do that too, but actually it will steal your important files such as text and document files, so be careful on saving your bank account or user/password information on your PC. visit : http://sureshotsoftware.com/guides/micro-file-virus/