Can not install Windows on M2. SSD

[Yilin]

Hello

Recently I bought an EliteBook 840 G3 oringally coming with only 500G HDD.

Today, I would like to upgrade it and buy a 256G M2 SSD.

Theoretically, in my mind, this laptop should support mixed disks and boot from M2 SSD.

After install the new SSD and try to install Windows 7 on SSD, I always get warning messages as below.

"This computers hardware may not support booting to this disk. Ensure that the disks controller is enabled in the computers BIOs menu."

Does anyone know how to install Windows on M2 SSD for 840 G3?

Thanks

[Huffer]

How do you have secure boot/legacy boot set up in the BIOS. For Windows 7 the legacy boot should be on and the secure boot off. 

[Yilin]

Hello Huffer

Thanks for your help. Yes, the setting in BIOS is the same as as you descript.
I acturally didn't change oringinal setting except boot sequence.

Regards

[Phantomas]

Hello,

could you give us more information on what you tried, have done during the installation process ?

I had a few issue while installing win 10 on my elitebook 840 G2 on a m.2 ssd, here is the way I worked it around:

- Make a new partition table (GPT) using GParted (I had linux on my HDD, but using a live-usb should work too).

- Make an esp partition (you can find a few tuto online on how to do so with GParted). (I'm not sure that's mandatory, but that way I was sure the disk was considered as bootable)

- Remove the old HDD during the whole install process.

The last one is REALLY important. The issue is that windows will ALWAYS try to install it's bootloader on an existing ESP. The problem with multi disk is the following:
IF windows install on your HDD, and you remove it/it crash, your install is now unbootable.
Thus, it'll alway prevent install on a non "active" esp/drive (which is the case on your newly installed ssd).
But if the m.2 is the only drive, even if there is no esp, windows WILL create one, and install without question or issue.

(I'd rather create myself a GPT partition table, as you can't know what windows will do anyway).

One las thing, I had difficulties booting windows on AC until I installed dirvers pack from HP, because my ssd was freezing. If the issue happen, remove the battery, press the power button (the trick will discharge everything) then retry booting while on battery.