Sounds like something is wrong in the database, as the 10400f does not have graphics. Maybe they were swapped somehow.
Download the 10400f driver.
So we can have more information about your system, Download, run, and save the results of this utility as a text file:
Then ATTACH the text file using the instructions under the reply window ( Drag and drop here or browse files to attach ).
This is a desktop system that has an add-in graphics card installed. By default, when the BIOS recognizes that an add-in graphics card is present, it will disable the processor's graphics engine. This is why you cannot "see" the processor graphics engine and this is why you cannot install the graphics driver package.
Considering that you have this add-in graphics card installed, the only reason for wanting the processor's graphics engine enabled is if you would like to connect more monitors than this add-in graphics card can support. If this is the case, you need to go into BIOS Setup and change the configuration so that the processor's graphics engine is enabled regardless.