Every browser has its good and bad moments, but it's sure seems like most moments are bad for Internet Explorer. Recently it was announced that people using IE 6 were vulnerable, even if Windows XP Service Pack Two is installed.
Microsoft reported one of these flaws last year, but there are still no patches for these flaws, which are described as "extremely critical" ones.
I imagine most people do not even realize there is an alternative to utilizing a different browser. When you buy a home computer, it already comes with Internet Explorer, so why bother trying to install another? There is a reason: There are other browsers out there.
If you're thinking of seeing the alternatives, try Firefox. I can tell you it's not perfect because it's the browser I normally use. But after time, you may even become enamored with it. That could be good or bad, depending on how much time you like to spend at your computer.