|"You ... " DO NOT "... need additional drivers in order to enable the numeric keypad. Is the numlock LED on?"|
The Num lock key toggles the Number pad key functions on /off.
When the led for it is on, you get numbers for 0 -9
When the led for it is off, you get the other functions of those keys.
If your keyboard won't work like that, it's defective, or more likely at least one of the wires inside it's cord are broken.
"try a different keyboard"
You can usually set whether Num lock is on (the led is on) or off when you first boot in the bios Setup.