1366*768 is the current resolution. I want to install nvidia graghics. I used to have it on here but I reset the machine to factory and now I can't install it again. I downloaded the driver from the hp web site for this computer.

That's the maximum resolution your laptop screen will do. No driver will increase it.

The website for my computer offers nvidia as a download option. Shouldn't I be able to install it?

It all depends on the maximum resolution of the display, NOT the drivers or graphics card employed.

You CANNOT exceed the displays maximum resolution.

Does your machine actually have the supported nvidea graphics card in it?

If not you will be unable to use these drivers.

It must have the nvidia card because I had it working before I factory reset the computer.

If you have the correct hardware then by all means get the latest driver for that video chipset, but it won't display any better than 1366 x 768.