Trying to see through the user's eyes

A patron I've never seen before came into my office to ask me about a problem with her computer. The following recreation is heavily edited.

P: The screen is all white!
me: What kind of monitor do you have?
P: The regular kind that sits on the desk.
me: I mean, is it a flat screen, like this one?
P: No, it's big.
me: Like a television? It might be a problem with your picture tube.
P: No, no, I can see everything, but the top and bottom of the screen are gone. It's all white.
me: So you can see the desktop, and you can see your Inbox?
P: Yes! That's what I've been telling you!
[I sign into Yahoo, open my Inbox, open my Inbox, and hit F11.]
me: Does it look something like this?
P: Yes! How did you do that?
me: I hit the function key F11.
P: What does that do?
me: Just what you see here. It makes the window go full screen and the menu bars and taskbar go away. Go home and try pressing F11 and see if that brings it back.
P: If there's no F11 key, can I just type F, 1, 1?
me: No, that won't work. There is an F11 key somewhere on your keyboard. You can find it.

Then there was a whole other conversation about leaving "the system" running for four months while she was in Florida, but what she really left on was the cable modem. Not a choice I would have made, but I assured her it didn't have anything to do with her immediate problem.