NVIDIA Guide on how to install the NVIDIA Display Driver Good: Express (Recommended)
Updates existing Graphics Driver files as neccessary, installs all optional driver components and leaves any custom NVIDIA Contol Panel settings intact.
Better: Custom (Advanced)
Updates existing Graphics Driver files as neccessary, installs only the selected optional driver components, uninstalls optional driver components you uncheck (except PhysX which can can be uninstalled in Windows Control Panel -> Progams and Features/Add or Remove Programs) and leaves any custom NVIDIA Contol Panel settings intact.
The Perform clean install option removes previous Graphics Drivers and NVIDIA registry entries from your computer and any custom NVIDIA Contol Panel settings.
Best: Display Driver Uninstaller (DDU)Uninstalls everything..The Graphics Driver, all optional driver components, custom NVIDIA Contol Panel settings, registry entries and old Graphics Drivers in Windows Driver Store, in Safe Mode.
If reverting back to an older driver, it's better to use the Custom (Advanced) clean install, and best to use Display Driver Uninstaller (DDU) in Safe Mode.
Best to install only the optional driver components you actually need..PhysX should always be installed.
Just my opinion..I always use DDU.