Cannot boot 2013 iMac... failed nvidia update?

[Shivetya]

2013 iMac with Nvidia 780m card.

Not sure what happened, had a request to update nvidia drivers and in middle of it system rebooted without asking. there was a dialog about security extensions needing to be checked but I did change those.

attempts to boot normally result in bar advancing then turning into the * that spins and just freezes.

it will boot into safe mode.

tried the power off, unplug for a while, reboot. no go

reset nvram did not help (did it both via keyboard and terminal (nvram -c)

booted to hardware test (D) and it did not find any issues but also did not give option to run more extensive tests

so looking for options to boot in normal. can i force it to use the apple driver?

perhaps reinstall OS X? Can that be done without deleting apps/mail?
[doublepost=1535632081][/doublepost]of course idiot me forgot I could restore a local snapshot... which worked

 

[techwarrior]

There are two ways to reinstall macOS. One is destructive, reformat the boot drive and install fresh. The other is to simply re-install over the existing drive without reformatting. The second method will leave Apps, User files paths, and user\system settings in place. So if the driver update corrupted OS files, this should take care of it.

Of course, Time Machine restores is always an option.