In Google I search like this "how to fix keyboard number pad" ?
Numeric Keypad doesn't work
Here I found the answer it works for me !
Changing the accessibility options on Windows 7 Control Panel l--------> Ease Of Access Center i--------> Make the keyboard easier to use
i----------> untick 'Turn On Mouse Keys'This fixed it for me. You can also change the setting for the mouse keys to enable it only when NumLock is offf