Question Can't boot Windows 10 in UEFI mode ?

[Buljic]

Hi everyone, hope u have a great day.
Here is the thing...

Right now I have Windows 10 PRO 21H1 (b1903) with MBR+Legacy boot.
System specs:

Asus Rog Strix B350-F
R5 1600X
XFX RX 570 4GB
16GB Corsair RAM on 2666MHz
Corsair Bronze 650W PSU

Since Windows 11 is coming I wanted to reinstall windows 10 in uefi+secure boot with ftpm enabled. But simply, I can not.
I've made bootable w10 media (Kingston 2.0 USB) and tried to boot from it. Partition 1 was USB:NTFS bootloader in my case, so I booted from there. It starts to boot, shows the Republic of Gamers logo, stays on it for a few seconds, and then reboots.
I have disabled Fast Boot, CSM, and secure boot. Boot mode is set to Windows UEFI but with all that it just reboots...

I was wondering, can my MBR Samsung Evo 850 prevent USB media from booting? Also, can DRAM voltage affect boot somehow? It's set on 1.2V

I have already installed windows 10 with gpt+uefi boot on some hp notebooks and it was quite easy to do, disable secure boot, delete platform key, reboot, and boot from USB, but this thing with my pc is starting to drive me crazy

 

[Buljic]

the format of your ssd right now, being MBR, has no effect at all on the ability of PC to boot off a USB. the reason I showed link was to point out what you should click in Boot Priority to boot USB.

where did you get ISO from? did you make it using the Media Creation tool?

You should have used Media creation tool to make USB as that Installer supports both UEFI and CSM boot so it should have worked.

I got iso from windows media creation tool and the rufus it to usb.

 

[Buljic]

You're doing something wrong.
UEFI installation media should be partitioned in GPT with single FAT32 partition.

Rufus way worked cause I installed windows 10 on hp 250 g6 in UEFI mode. Like I said, It was so easy, enter the bios, disabled secure boot, deleted platform key, and boom. Later after installation, I enabled secure boot again with no problem

 

[Buljic]

View: https://www.youtube.com/watch?v=ATJVWHfQsY8&t=828s

 

[lance88]

If your drive is MBR and need to convert to GPT in order to use in UEFI, you dont have to reinstall the entire disk

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.

 

[Buljic]

No, thing is, even if I want to reinstall OS, I can not. I can't explain it more clearly. USB, FAT32, UEFI non CSM. Bios -> CSM Off, PK Enroled, Secure Boot Enabled, Windows UEFI boot mode. It simply won't boot into windows setup. MBR disk shouldn't make any problems. In fact, I've tried with some old sata hdd, converted it to gpt, and still can't boot from USB. I am assuming that my motherboard is faulty.

So with all of this said, I don't want to reformat my disk into gpt because it most likely won't boot anymore into windows.