Every now and then on several different sites I go to keep changing into a different page with a voice saying that it is a "windows alert" and it has a bit screen of scrolling text behind it. As soon as it pops up I close the tab and reload the page. Is this something I need to be worried about? The first few times I popped up I closed my internet and did a McAfee scan, but it's never found anything, so now I just close the tab and reload the page. It mainly happens either here or on Comic Book Resources.