Well.. A virus is a potentially damaging computer program that affects a computer negatively by altering the way the computer works. Or sends false alerts. Or just harm your pc but at the same time saying its fine. Vista IS THE SAME!. The difference is that. A virus THATS HIS JOB. Well vista... No comments on that... Hahaha, lol? Liked it? It's kinda bad, i know, im not a good comedian