HP z620 Nvme SSD Boot - Yes you can! Windows 7 install and boot

[MsWakeUp]

Hello,

A lot of people say that you can't boot from Nvme SSD using z620... But you can, and I will tell you briefly how to do
it! I have installed Windows 7 SP1 and am booting it, so we will be talking about Win 7 here and surely this should
work for other versions of Windows - 8 - 10 - 11... I won't give you a step by step guide but will tell you HOW to do
it, and can help answering questions.

So what do we need:

1. NVME SSD pluged in to PCI slot - i have used this one 

SK hynix BC511 256 GB with GPT structure

with

2. Windows 7 SP1 ISO with integrated NVME driver - you can find it yourself or integrate NVME Driver using Gigabyte windows usb installation tool.

3. Bootable Flash drive with Clover bootloader on it - google how to make it...

Steps to install Windows 7:

1. Create additional disk by shrinking your current HDD or SSD drive and format it with FAT 32.

2. Extract the contents of  Windows 7 SP1 ISO with integrated NVME driver on this newly created drive.

3. Boot from Clover  USB Flash and enter UEFI console 

4. From the console go to the drive where you have extracted the contents of  Windows 7 ISO

5. Go to efi\boot directory on this drive and run bootx64.efi - the installation will start.

6. IMPORTANT STEP - Choose advanced installation and delete all the partitions on your NVME SSD - create new partition - Windows SetUp should inform you that additional partition for system files will be created - say Yes. (This additional partition for system files is the most important thing) 

7. After that Windows might not allow you to continue setup - click the button - Load Driver - and let Windows search for the drivers - we dont need drivers but clicking on this button will make Windows think that we are installing something. After that exit the driver search dialog and start setup again - now Windows should allow you to continue SetUp - there can be a warning that you won't be able to boot but just ignore it.

8. After the setup restarts boot from Clover USB and go to the console - here you should go to your NVME drive and head to  efi\boot directory on this drive, and run bootx64.efi   (like we did it before but on the other drive to start Setup).

That's it! Your installation will continue and finish - if the computer will restart once again during installation - continue setup - like in the last step 8.

Clover bootloader will ad an entry for booting your Windows without console

You will have to always boot from Flash USB but you can install Clover on your HDD/SSD and boot normally, I haven't done this yet but will do in the nearest future)

Good Luck!