I've got a laptop with a GTX 840M, and I've been noticing that my games have been running extremely laggy recently - single digit framerates are normal. I recently reformatted my laptop, and after it's showing 'Microsoft Basic Display Driver' in my dxdiag. Also, if I try to go to Nvidia's Control Panel (not Geforce Experience) then it tells me that I'm not using a display that's attached to a Nvidia GPU. I've tried uninstalling and reinstalling my Nvidia drivers, with no success.