Try right clicking on desktop and going into the Nvidia control panel.
Click manage 3d settings on the left, the select Dolphin from the drop down list.
Set it to use the Nvidia card and restart Dolphin. You may have to open the graphics
properties menu twice, but it should then say Nvidia and be using that card
EDIT: Use Dolphin 3.5, fixed the problem for me (I have an HP laptop also.)
Click manage 3d settings on the left, the select Dolphin from the drop down list.
Set it to use the Nvidia card and restart Dolphin. You may have to open the graphics
properties menu twice, but it should then say Nvidia and be using that card
EDIT: Use Dolphin 3.5, fixed the problem for me (I have an HP laptop also.)
~ AwesomeMarioFan