I dropped my photosmart m525 camera. and now, when i turn it on, it says lens error:12?

what can i do to fix it. ?

If still under warranty (usually 1 year) send it to HP to get it fixed. But if they realize that it was dropped, the repair will not be free. Or you can take it to a camera repair shop. This is most likely not something you can fix yourself.

it needs repaired by a service center