What ever I use the numeric keypad on the Apple Wired Keyboard on Windows 7 boot camp. It does not work. I have to use the number on the above of my letter case part. I tried using the numeric keys on calculator or games. It functions more like fn, home, page down, page up. WTH? Why is it functioning like the keys between the numeric keypad and keyboard? The drivers installed just fine and I got all the windows updates along with apple updates. I even went to keyboard options in boot camp control panel and it still does not work.
Here is your answer - just found it on MacRumors as I was experiencing the same problem. Ready - got a pen and pencil available: Hit "Clear" lol, yup, that is your on off button for the numeric pad. :-) Be sure to share with others.
The "Clear" Button is located above the number 7. 65431354684318643516879 <---- numerica keypad fun.