Forgot, I suggest you remove your service tag

Hello,

First, the sata controller has to be disabled if you want to install on the nvme ( and have it still working after rebooting )... so disable ALL sata ports in the bios.

Then Raid must be off ( so AHCI )

Advanced boot options >> enable legacy option roms

Secure boot : Disabled

Third condition is using

https://dl.dell.com/FOLDER06025383M/1/Intel-Rapid-Storage-Technology-Enterprise-Driver_660HV_WIN_6.2.2.1007_A11.EXE

this when booting the installation media ( unzip it on the media and load it at the appropriate time ).

If this version of the driver doesn't work, use this one

https://www.dell.com/support/home/en-us/drivers/driversdetails?driverId=TV5DJ , aka Version 5.3.1.1019, A03.

I misplaced my notes so right now I'm not sure which of the 2 worked for me to install windows on my T7820 ( i've both saved in a folder and on the media )

Once windows is installed, you can reactivate the sata controller / channels.

If the sata drive is formatted as EXFAT windows will  not offer the drive as something to boot and install on.

I know this is fact because thats how I format drives set as AHCI  EXFAT.

The F6 drivers are not optional.

Navigate to SATA Operation and choose AHCI

Doing this will also remove the drive as boot option in bios.

You cant have it formatted UEFI GPT with an MSR because windows will become confused.

Bios is not a boot selector for multiple GPT UEFI Drives

Formatting EXFAT is MBR

This pre install driver will need to be extracted and on the root of your USB install media. You cannot point to a cab or exe or zip file.

7Zip  is the best option for extraction but intel also provides instructions in the notes.

https://www.7-zip.org/download.html

Internal SAS raid devices use a different F6 driver for LSI Controller.

https://downloadcenter.intel.com/download/29978

%PCI\VEN_8086&DEV_2822&CC_0104
%PCI\VEN_8086&DEV_282A&CC_0104.
%PCI\VEN_8086&DEV_A286&CC_0104.
%PCI\VEN_8086&DEV_34D7&CC_0104.
%PCI\VEN_8086&DEV_02D7&CC_0104.
%PCI\VEN_8086&DEV_06D6&CC_0104.
%PCI\VEN_8086&DEV_06D7&CC_0104.
%PCI\VEN_8086&DEV_A386&CC_0104
%PCI\VEN_8086&CC_0108.DeviceDesc% = NVMe_inst, PCI\VEN_8086&CC_0108

Sorry @speedstep  but it was dell Prosupport that told me to disable sata to install ( and install only ) windows on a pci-e nvme installed in the flexbay.

There's even documentation about it.  : https://www.dell.com/support/kbdoc/it-it/000132465/windows-10-install-with-nvme-ssd-and-sata-drives?lang=en

Not doing it causes the installation to not work correctly after rebooting

You Must set sata operation to AHCI

And you must use a PCI-E NVME Card if you do not have an PCI-E NVME onboard.

Booting from an NVMe PCIe SSD is only supported on systems that support UEFI and the slot must be PCI-E 3.0

Disabling sata controller is bad advice and wrong.

In order for Windows to "see" the NVME Drive F6 Mass Storage drivers must be installed.

The procedure is the same for XP/VISTA/7/8/10

how to install the  f6-driver-during the windows installation setup process

https://www.dell.com/support/kbdoc/en-us/000148150/

PCIe* with NVMe* interface as a boot drive.

Boot Installation Guide (PDF)

.This is M key only AHCI drive

Well, that's relative.

Those were the instructions I got given under warranty to reinstall on a wiped nvme boot drive ( and no other hdds installed in the system ).

I failed installing at all without following them, including disabling the sata.

Put the sata drive in a dock or some other medium and use diskpart to clean the drive

Going over the manual the Flex Bay NVME are SATA not PCI-E

There are 2 kinds of NVME PCI and SATA they are not interchangeable

You will have to mount the drive on a card and plug it into PCI-E slot

https://www.amazon.com/Adapter-Express-Support-Windows-Speed/dp/B07GP9WLCR

Secure boot should be OFF so that you can F12 boot your install media.

https://www.amazon.com/ORICO-Duplicator-Function-Protocol-Supported/dp/B00JJEUL5W

Then partiton the SATA drive As MBR EXFAT.
Disabling SATA is not recommended or required

Sata operation should be set AHCI that is required

Once the drive is installed and formatted You Can Assign it a drive letter like E:

https://www.bestbuy.com/site/sandisk-cruzer-32gb-usb-2-0-flash-drive-black/9288807.p?skuId=9288807

You will have to use a  16 gig  or 32 gig FAT32 USB2 flash drive 

and once created  using the tool

https://go.microsoft.com/fwlink/?LinkId=691209

you will need to download the INTEL F6 driver and extract the files from the zip onto the root of the flash drive

You cannot point to a zip or cab or exe file.

When windows prompts to install a driver you point to the flash drive

And load the NVME driver

Some Vendors like samsung have their own driver

There is no one size fits all

There is support for what you want to do.

Said support is not free.

F6 driver loaded refresh and it will see the nvme drive

I'm not going to weigh in on who is right, but Mazzinia's solution worked for me. By the way, the first driver he listed did the trick.

Thank you!  This fixed worked for me.

Mazinna's fix worked for me.  I'm glad I tried his before scrolling down and reading your comments.