The new Intel processors with integral graphics are presenting new problems with configuration and setup that we are all learning about. Your post is the first time I have heard of this issue cropping up on a desktop. Perhaps others here have more information than I have. I do not own or maintain any desktops with integral processors, so I just have not had to deal with it....... yet.
There has been a discussion and discovery session going on here
Acer Laptop: Switchable Graphics using i7 & AMD Radeon regarding the issue on laptops. As you can see from that thread, no one has found a satisfying solution to the problem of manually choosing which graphics to use yet.
For the laptops the solution will be found in the BIOS settings and/or the laptop graphics
drivers. It really comes down to a matter of: did the motherboard manufacturer recognize the need and design in a 'switch' to allow for user setting/disabling of the integrated graphics?
For your desktop situation the first thing you want to check is whether there is a setting in your BIOS that will allow you to disable the Intel graphics on the processor. There is not a lot of danger, in a modern system, to making changes in these settings. If something goes wrong and you could not boot there are ways to restore the BIOS default settings to recover fairly easily.
General advice: before starting any BIOS settings edits, always record your current settings so you can set them all back easily if you ever need to restore defaults.
But keep in mind that the way this new tech is supposed to work is that the computer will use the low power integrated Intel graphics when there is no need for graphics horsepower and automatically switch to the graphics card/chip when horsepower is called for. In the laptops anyway, there seems to be a lag in the tech for the performance testing software where the software does not 'know' to call for the system to switch to the higher graphics. It seems the software itself does not need a lot of graphics muscle to run so no switching occurs and the test are run on the Intel graphics only. (Note: my hypothesis)
So one annoying answer is to leave it alone and stop running tests until you run into a performance issue while gaming that justifies it.
But as you can see in the above post, it is merely the fact that you don't have the choice that is aggravating most people.