There is another trick they do. You could be on the web just doing your thing and a window pops up with the little shield and says they are scanning your computer because you have a dangerous virus. If you click on the x to delete the page it starts to run like crazy. If such a page pops up, do not x it out, just do ALT, CTRL, DELETE, on you key board and end the process there to get rid of it and then it can't run. This happened to me a couple times and after I got rid of it, I ran my virus program right away.