Laptop Keyboard Not Functioning

Try to unplug and plug back in the keyboard connector ribbon onto the motherboard. Consult the laptop manual if that voids your warranty or not before trying, also look at the documentation on how to dissemble your laptop, it shouldn't be too hard. here's the instructions on how to do it

http://support.dell.com/support/edocs/systems/ins2600/en/sm_en/keyboard.htm#1005330

you might need some tools, but good luck and be careful