On Dell laptops, the OEM graphics driver package has an embedded mechanism called "Optimus".
Optimus is supposed to do the switching between Intel Onboard graphics and NVidia graphics cards.
All is well, as long as no bugs surface and you stay with the Dell supplied drivers.
And there lays the problem.
NVidia doesn't release regular driver updates just for fun!
They do that to fix bugs in their drivers, which are plenty.
Dell driver support lags far behind, and even stops 1.5 years after you bought the laptop.
So, in despair and notwithstanding the warnings, you try the NVidia supplied drivers.
However, by doing that you wreck the hardware dependent Optimus installation which is not provided by NVidia.
NVidia supplied driver releases may
work on your computer, but sometimes you even can't get them installed.
In my experience and on my particular laptop, (Dell XPS15 i7/NVidia GT540M), graphics driver maintenance is a lottery.
It took me >2 years to get a driver suite that works, but only on an under-clocked
But now it works, and I can finally finish a race on a HD scenery without a total system crash.
I don't even dare
to touch graphics drivers on this machine anymore.