In fact you will have to look at every model and design of the
notebook in question. Unlike PC modding with hardware and cards
readily available in retails for upgrade and replacements, the
notebook assembly process is very different. Older models may have
the graphics integrated on the motherboard so replacement of
graphics means replacement of the whole system. If you are getting
the newer models with the nVidia GPU and
mobile graphics card as shown with my link most probably you can
upgrade. Otherwise you may just have to check with the notebook
manufacturers on the availabliltiy of any graphics card for
replacement. Other than the graphics and motherboard, hard disk,
random access memory, USB expansion and other
add-ons upgrades should not be a problem for most notebooks.