Ah, so you fiddled with Nvidia drivers rather than let Windows updates do it.
You did not say.
My Laptop has the same GT 740M in there, the driver is 376.54 which works. I don't care if it's a year old.

Further essential basic checks is to the temperatures of the CPU, GPU etc.
I use HWMonitor from CPUID which works on my Laptop which has the same GT 740M in there.
Fan revs are monitored by a Toshiba application.

After so many years, fans need cleaning or replacing(hence the temperature and revs check), HDD probably close to retirement.
You say most problems have been removed, further work needs doing.