First, you have to disable Secure Boot and enable CSM mode in bios. I would start with a new hard drive and not erase your original in case things go south. Use the drivers in your eSupport folder (many of them still work with Win 7). You need the following USB driver (or newer version) from Intel site:
Intel(R)_USB_3.0_eXtensible_Host_Controller_Driver_4.0.0.36 (no longer available on Intel site, but the newer version should work).
Download the newest video drivers from Intel (win64_154014.4352 & latest nVidea) & Nvidea site. I unzipped them all and used ImgBurn to create the iso and then burned it to a blank DVD. Once Windows 7 is installed, use device manager to select the DVD and load chipset drivers first, followed by MEI, DPTF Intel, USB 3 Extensible, Network, Intel Wireless Network and ATK (for lighted keyboard), Card Reader, then update both video drivers (I think those are the major ones you need). Until USB is installed, navigating without a touchpad or mouse is the biggest frustration (use Alt-Tab and Windows shortcuts)
