A Windows user states that every time they hit certain letter keys on their notebook, a
number appears instead of the letter. Which of the following items is MOST likely the cause
of this problem?

A.
The user enabled sticky keys.

B.
The user changed the keyboard character set.

C.
The user enabled accessibility options.

D.
The user enabled num lock.

Explanation:

Reference:
http://www.howtogeek.com/forum/topic/crazy-num-lock-problem