Number lock issue on HP Laptop

I have an HP Laptop on which i had installed Windows Vista as my operating system. Now the problem is that when i turn on my system, after 30 minutes my number lock comes on and then on the right hand side of the keys it will give me numbers and symbols instead of letters. I can't take the number lock off without turning off the computer and taking the battery out. Can any body tell me that why i'm having number lock issue on my HP Laptop? Does any body knows about it? Kindly help me out withe above issue.

Num Lock is a key on the numeric keypad of most computer keyboards. It is a toggle key, like Caps Lock and Scroll Lock. Num Lock key is located on the numeric keypad of the keyboard and enables and disables the numeric pad. Its state is commonly represented by an LED light built into the keyboard. Turning the Num Lock on will allow the user to use the numbers on the keypad and turning the Num Lock off will enable the keys other functions such as using the keypad as an arrow pad.

This is due to the fact that the digital lock is activated. To solve this, simply press the Fn+Numlk or depending of the model, press the button or Fn + Shift +Numlk .The status of the NUM LOCK key is specific for each user, and NUM LOCK is disabled by default. If you want the NUM LOCK key enabled for use before a user presses CTRL+ALT+DEL to log on, you must use Registry Editor to change the default behavior.

However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. On most keyboards, pressing the num lock button will turn it both off and on, just try pushing it again. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. or more information, you can check out the following link.