1. First step is to go to your search icon on your taskbar and search for device manager.
2. Then click on Device Manager (shown below in the red rectangle).
3. Find you device that you are trying to manually add the driver to it.
4. Then right click the device and click Properties (example shown below).
5. Next click the tab on the top of the windows that states Driver.
6. Once you have done that, click on Update Driver.
7. Once the new windows pops-up click Browse my computer for drivers.
8. After you selected that, click on Let me pick from a list of available drivers on my computer .then click Next.
9. After you have done that click on the right type your hardware is.
10. For the final step select the devices manufacture and model of the device and then click next. Once you have done that it should install the driver you have selected. (Each device requires a specific driver. The one in the image is just for a example.)