Nothing new about Mac bashers, or dumb windows users. You can try a logical question, such as "when was the last time you used one?", but using such logic is generally a waste of time. But, as a hard-line windows IT type once told me, "Windows pays my mortgage". Dumbest questions I hear from some windows-only users: (no particular order)
-"Where's the start button?"
-"Where's the C drive?"
-"Can you run office? I heard you can't run office."
All classics. If you really want to mess with them, ask them where the B drive is. Odds are, they won't have a clue. (It comes from the original IBM PC's. Had two floppy drives, the second one was B)
Mess with them some more. Most windows users don't know that pressing the windows key, and the letter E together pops open an explorer window. No really, they don't know this simple keyboard shortcut. After you show them this, tell them "you just learned that from a Mac user". Be ready for a classic, Deer-in-headlights look, or a look of disgust.
Still, it must be killing them, with Apple's Market cap (what a company is worth) being about 15 billion higher than Dell's, and the now infamous email from Jim Allchin, saying that he would buy a Mac, if he were not employed at Microsoft. (They are spin controlling this, of course)
Oh, and how about this classic, for when there they have no other response: "Well that doesn't prove anything!". Uh-huh.