Yes, anything with a clock can be overclocked, but unfortunately for those big OEMs HP and Dell, finding out which generator they use is a pain and so far havent had any luck with it yet.

Anyway for overclocking laptops, if it could be done, I think should have no harm as long as you keep within the highest thermals it is designed for - so I suppose it will still be safe to clock it as high as the highest CPU model offered for that notebook line.