Problem with function-key with Acer/Samsung laptop

I have an ACER laptop model TM4152LMI with Windows XP installed.

The problem is the function key acts as if it is being held down, therefore
a section of the keypad turns into a number pad. I have had the same problem with another Samsung laptop, and fixed it with a format, however this seemed a little overkill for solving the problem, I just got frustrated.

The keypad works as normal if you hold down the function key, as if its role has been reversed. It seems to be the same as the scenario of holding down shift as oppose to hitting caps-lock, however there doesn't seem to be a 'caps-lock equivalent' for this situation.

The problem started after adding a ps2 keyboard to the system, and then removing it. The frustrating part is the laptops keypad works the way it should with the ps2 keyboard plugged in (but this defeats the purpose ).

I have tried plugging the keyboard back in, rebooting, removing it, rebooting again, etc, to no effect.

As far as I can tell this is a windows problem, I was just wondering if there was a nice easy fix for it. (ie, just a simple key combo to disable it)

Thanks in advance

yer a life saver. I've had this problem for a while. Wasn't a big deal since I have a back up wireless keyboard, but using the installed keyboard was a pain. It works now...yay!