Get them from the HP support website that's appropriate for your region.
You will need the
complete model number of your laptop, for example
Compaq Presario CQ57-229WM
The complete model number for yours should be printed on a sticker underneath the laptop - - - copy it on to a piece of paper for easy reference.
Then go here & choose the appropriate region & country:
http://welcome.hp.com/country/w1/en/support.html