[Hank Rearden]

I believe Windows XP was based on Windows 98.

Bzzzzt! Wrong! But thanks for playing our game. We have a home edition to take with you as your lovely parting gift.

Sure hope you don't work tech-support lines. On the other hand, I think I've talked to you when I've had to call . . . . .

[DennisR]

"I believe Windows XP was based on Windows 98."

Settle down, Hank. As I said, "I believe." Did I say I knew for sure? No. Because did I know for sure? No. And that is exactly why I chose the phrase "I believe," which is often used to express the fact that you think you are right, but you aren't sure. Which is exactly what I was trying to express, because that was exactly what the situation was. In other words, you did not need to waste time both your time and mine making smart remarks.