How to install Windows 7 on Skylake Dell XPS 8910

Just got a Dell XPS 8910 with the i7-6700k skylake which comes with Windows 10 installed.
I would like to install windows 7.

Following this video made a windows 7 bootable USB from a dell windows 7 ultimate disc. How to install Windows 7 on Skylake platform using USB device - YouTube

When I am on the 8910 and try booting to the USB though the keyboard and mouse still dont work, not sure why. Bios are still UEFI. Would like to install this to the HDD it came with not the SSD and test that Windows 7 even works on skylake. (oddly if i hit cntrl-alt-delete in the same screen it reboots.) The computer has 3 sets of USB ports

Any suggestions to make it work or bios settings? There are some odd ones with the 8910 I have not seen before such as load optional rom and something about loading OS [2].

Here is the USB layout, I have tried the 3.0 3.1 2.0 and nothing seems to work...
XPS 8910 Desktop - Intel i7 Quad Core Processor | Dell Philippines


thank you.

First, make your Factory Recover disks. If something goes wrong, you can get back your computer as it came from factory.
You don't have mouse and keyboard because your motherboard has USB 3.0 and Win 7 doesn't has the the driver.
Look my tutorial
Create a Windows 7 USB flash installation with new drives for new MB's

Thank you for offering this solution, do you know what type of motherboard is in a Dell xps 8910? Tried calling dell but was told they do not know which may mean its generic? Are there any tips for being able to identify the type of motherboard or manufacturer as mentioned in the linked post you provided?

Thank you.

Look for what chipset you have. Quite sure it's 100 series.
Download the drivers and patch them into your installation disk.
Use this software https://www.hwinfo.com/

I've seen your specs: It's a Z170

Se attached files

On BIOS, you must disable secure boot and enable CSM
On CSM use UEFI options

To create recovery media for the Dell XPS 8910, are these instructions correct? Create Windows 10 recovery media for your Dell computer | Dell US

Worried that if I try to isntall windows 7 to the SSD it might fail and then its messed up. Will that link if I follow it give me what is needed to resinstall the OS and set it back to the factory settings as mentioned earlier?

Normally OEM computers has a partition that has the Factory Recover. With it, normally you can make a Factory recover (From BIOS or from Windows) and / or make the Factory Recover disks that allow to reinstall on same disk or on a different one.
The link you provided is another way to make the Factory Recover disks.

Answers:

*So i can ignore downloading the drivers in first post and just use the files in the second post? Yes
*Secure boot is disabled with UEFI enabled - Good
*I do not see CSM or know what that is? is that just booting to the usb drive? I can choose that in setup if that matters on the load screen... maybe its enabled by default? - No problem. Some MB don't have it.
*My 8900 had Win 7 Ultimate and it would be nice to reinstall that on this new 8910. It's possible but won't be legal if the license is OEM.

To use another SSD or HDD to install Win 7 is the best and safest solution. Remember to disconnect all other SSD and HDD from the MB.

Once you have success on installing Win 7 all give you more tips to move the Users folder to D: