Code 43 is just a generic error, it typically indicates a problem with either software(driver) or the hardware..
I would uninstall the Nvidia driver, then reboot before installing one, so that Windows just loads generic video drivers. You may even have to do this in safe mode. Are you getting the error in Device manager then? What about in Safe Mode? Install a fresh Nvidia driver only after you've cleaned all old drivers. The card may be toast, just try a few more steps before changing it, seems it is not completely dead if you still see your desktop at all.
Also, I think there was some Nvidia code 43 error issue with the Windows 10 May 2019 update and Intel Sandy Bridge CPUs, there may be a hotfix available, or definitely try a different version of the Nvidia drivers.
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