A Mac user we know contributed these messages that allegedly are under consideration for Windows 2000.
 

Smash forehead on keyboard to continue.

Enter any 11-digit prime number to continue.

Press Ctrl-Alt-Del now for IQ test.

This will end your Windows session. Do you want to play another game?

Error saving file! Format drive now? (Y/Y)

BREAKFAST.SYS halted. Cereal port not responding.

File not found. Should I fake it? (Y/N)

Runtime Error 6D at 417A:32CF: Incompetent User.

User Error: Replace user.

Your hard drive has been scanned and all stolen software titles have been deleted. The police are on the way.