What does the "pause" and "break" key normally do on Windows?

Good question, I've always wondered that. I do know that if you press the Win key+Pause/break, it will bring up your system info.

EDIT: Just found this:
The Pause/Break key was used in the DOS command line environment to pause scrolling of text on the screen, which could, depending on the program and its method of text output to the screen, have the effect of pausing program execution. The Break key, when combined with the Ctrl key, is used to terminate DOS applications - and still does today, even in the DOS window of Windows XP.

if u press pause/break key when you power your computer on it will pause the bios/hardware/memory checks etc and will only continue when you press the enter key also Ctrl-Alt-Break is a key combination used in windows remote desktop to reduce a fullscreen remote desktop session to windowed mode.

It's been around way before Windows-based PCs. Try computers with BASIC. Mainly, it just pauses the execution of the program that is running. In current Windows OSs though, it doesn't do much. Windows+Pause gets the system information window, and that's about it.

Windows key + pause give you your system configuration stats.

I know I used it all the time in DOS: If you used the Soundblaster 16 organ, you could pause music If you were playing a game like Jill of the Jungle or Xargon, you could pause the game If you typed "dir" you could pause the listing of files

On older computers, like mid 90's you could hit it while your system is boot so you could see information about processes as they load

So basically, they should just rename it "The Any Key" and those that are still out there looking for that will finally have something they can push.

Just kidding.... all information about is good info, for anyone out there still dabbling in DOS.(although I can't say as I know any other than myself from time to time)