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It's to allow you to use the Intel driver during install rather than the included driver in Windows. Sometimes the included drivers are basic and full function may require motherboard or device manufacture drivers.
I usually wait and install the specific drivers later if required. If your system is functioning normally, the included drivers may be adequate.
On Win 10 you don't need Intel SATA Preinstall driver as the Win 10 installation disk already has it.
You needed SATA and USB3.x drivers to install Win 7 as the Win 7 installation disk doesn't have it.