iMac Keyboard #s Pad Won't Work in Windows

I'm running Windows XP in Bootcamp, and am having difficulty getting the numbers keypad to work on my standard aluminum iMac keyboard.

Can anyone help me to get it working? The rest of the keyboard seems to function without any problems.

Well, for those who ever need an answer to this question, I've figured it out. One just has to hit the "Clear" key on the iMac keypad, and it turns on the number keys on keypad; just like with the "Num Lock" button on a PC keyboard.

EORI, you're a bloody genius! I've ben trying to solve this problem for ages. I can't believe the solution was so simple! I must have tried every key except the "clear" key.

Thanks.

A little off topic, but why do PCs even have a number lock button anyway? Do the keys function as something else when it's not on? Why would you ever want it off? I just don't get it.

Yes, they do have other uses for those keys. 8, 2, 4 and 6 are up, down left and right arrows (in that order). 7 = home, 1 = end. 9 and 3 are Page Up and Page Down respectively. The funny thing is when you look at the position of those keys on the normal keyboard - they're right next to the number pad, so why bother?