Who Needs Antivirus Software?

One day after booting Dad's computer, McAfee Antivirus immediately popped-up warning that it detected a virus. After clicking "remove threat" (or something to that effect) the pop-up disappeared, only to reappear a few seconds later indicating that it had detected a virus. After trying a few things, I could not come up with an easy solution to make this infinite loop pop-up go away.

I mentioned this to my Dad. "Did you know that your computer has a virus alert?" He responded "Yeah, I wasn't sure what to do about that, so I've just been dragging the window into the corner and ignoring it."

Sigh.