Go here http://h10025.www1.hp.com/ewfrf/wc/siteHome?tmp_forceView=desktop&cc=us&dlc=en&lc=en
and enter your laptops product number. It should look roughly similar to mine: NB634AV. If you do not know the product number there is a link below the product # box with a guide to finding it.
After you have entered the product # click "Drivers and Downloads" and then follow the on screen prompts.