There are a couple of reasons why the keyboard wont work.
But ask yourself the following questions
Can you enter the BIOS, look for a message when you turn the laptop on asking you to "press DEL or F12 or similar) to enter Setup/BIOS, if not then
then keyboard is faulty.
If you can enter the BIOS but the keyboard stops responding when Windows starts up then the drivers are faulty, this can happen.