[SOLVED] Need help with UEFI only boot mode

[vegasjon777]

H all:
I have an ASUS ROG Z370-e mobo and am trying to enable UEFI only boot mode without legacy options. I've gone into the bios and enabled UEFI ONLY under Boot Device Control, LAUNCH CSM is ENABLED, and under Secure Boot OS TYPE is Windows UEFI MODE.. Then when I save and exit, it wont post, just puts me back to the BIOS screen. If I switch UEFI to Legacy it boots fine into Win 10. Any thoughts on what I am not doing right?

 

[MeanMachine41]

(CSM) Compatibility Support Module is a component of the UEFI firmware that provides legacy BIOS compatibility by emulating a BIOS environment, This allows legacy operating systems and some option ROMs that do not support UEFI to still be used. Disable CSM
Disabling CSM will disable Legacy Mode on your motherboard and enable the full UEFI Mode that your system requires. The PC will restart and will now be configured in UEFI mode.

 

[lance88]

I found the answers hence sharing here for those that need to:

https://docs.microsoft.com/de-de/windows/deployment/mbr-to-gpt?ranMID=46131&ranEAID=kXQk6*ivFEQ&ranSiteID=kXQk6.ivFEQ-HYF4.x9QUSSl6AxR2Zv4Jw&epi=kXQk6.ivFEQ-HYF4.x9QUSSl6AxR2Zv4Jw&irgwc=1&OCID=AID2200057_aff_7806_1243925&tduid=(ir__tiiqswk92ckf60gaiyumtzj9rf2xra91rkcamwya00)(7806)(1243925)(kXQk6.ivFEQ-HYF4.x9QUSSl6AxR2Zv4Jw)()&irclickid=_tiiqswk92ckf60gaiyumtzj9rf2xra91rkcamwya00

Checks if your drive is MBR format

Follow the link to convert MBR to GPT, you will need to use /allowFullOS to work.

You can specific the disk number if its not 0. Eg, mbr2gpt /validate /disk:0 /allowFullOS

Once completed, restart and boot immediately into bios page and change boot mode to UEFI and viola.



If you yet to have windows installed, you can refer to the below solution:

-Have a USB and create a bootable win

-Remain boot set as UEFI and not CSM/legacy

-Have Windows 8.1/ 10 WHQL Support"="Enabled"

-Boot using the USB and initialize the drive as GPT then begin the installation

You should able to see nvme ssd at the end result while remain as UEFI bios.