Could you provide a little more detail, please? I'm uncertain what to do with this INF file, as I'm assuming from your post I actually need the drivers from elsewhere but am not sure where to obtain them. I presume I need the INF file to install the drivers. I have the official (non-zadig) drivers installed (noted above) but you remarked they are not the same. Any clarification you could offer would be much appreciated

When Windows prompts you to install a driver, one of the options is to browse for an INF file. In this case browse to the GridSeed INF file found in the link I provided.
In the case of Windows 7 and 8 and 8.1 you will need to take extra steps (different for each) to install unsigned drivers.