You want and need to completely uninstall the drivers of your previous Graphics Card (either integrated or external).
What you are looking -is here:
Display Driver Uninstaller (From Guru3D)
www.guru3d.com/files-details/display-driver-uninstaller-download.html
The best solution to completely uninstall any obsolete or defective driver from your system.
Or if you want to install a gpu from another manufacturer and need uninstall the anterior drivers.
NOTES: Enter safe mode to ensure… See More
total cleanliness of the driver to be uninstalled.
Remember to restart the PC after uninstalling.
I recommend that you use ccleaner to clean the system after the reboot.
If what you want is to uninstall a program in its entirety I also recommend
IObit Uninstaller
www.iobit.com/es/advanceduninstaller.php
It is a great tool, I am personally using it and I have obtained incredible results.
Have nice Hunt.