Getting back my keyboard driver
 

Using Vista Home Premium: I plugged in a USB 102 key keyboard in my laptop
the system found the driver and worked ok. On disconnecting the keyboard
(and restarting the laptop) I've lost the functionality of the laptop
keyboard (need to press Fn key to access some normal characters. Looked in
control panel - keyboard but did not see original driver.
Can someone help me retrieve my original driver.
Thanks.