If you cannot enter numbers on the numeric keypad, check if the Num lock icon in the desktop notification area is green or gray. When the icon is grayed out, the numeric keypad works as the directional arrow keys and the Home, Page Up, Page Down and End keys. Press the Num Lk key to change the Num lock icon to green before entering numbers.

Check if the Caps Lock indicator light is on or off.

When the indicator light is on, characters typed will appear in uppercase (or lowercase if you also hold down the Shift key).

Press the Caps Lock key to turn the Caps Lock indicator light on or off. See Parts and Controls of the Keyboard for the location.