hi

i have purchased a B450 pro 4 with a ryzen 7 1700.  Machine boots fine but the samsung M.2 is not booting - it already has a OS installed. It doesn't show on the boot options.

Anyone from Asrock know why?  bios is only one available. 

Looked ion to the options and nothing shows. 

under storage configuration, the samsung m.2 drive is showing on that screen under my other 2 drives.

when i go to install windows from a usb drive, the drive is detected to install but cannot install to it as it has a GPT partition.

in bios check boot tab, there should be CSM, harddrives should be set to either UEFI only or both legacy/uefi

boot files are on EFI partition (around 100MB),

as long that partition contains valid data, bios will see it

sooo, if u still cant boot, u will need to repair your efi partition

https://www.easeus.com/partition-master/restore-repair-deleted-efi-boot-partition-in-windows-10-8-7.html" rel="nofollow - here is some guide

thanks, did all that, and it only looks at the unallocated partition which is 1mb.  the EFI is there. i think i'll install windows over the existing one, that way i get my files back.  really annoying though!

you might have to pertition it again with partition magic or something

and then install as uefi

how did u install it

m.2 drive has MBR or GTP?

if its GTP, EFI partition exists?

CSM is legacy or UEFI?

hi all.

ok, backup my data anf deleted all partitions and formatted the drive.  i then reinstalled windows as uefi as previously done onto a blank unformatted drive and let windows create the partition, doesn't detect it in the bios and then blue screens saying media is required.  boot from SSD that is on sata port and fine, works no issue.  Took the m.2 out as didn;t work, put my other 2 drives back in, neither has windows on it, on start up, blue screens with the error windows code and has select other oc when F9 is pressed, and this brings 2 os choices up when only 1 drive has windows on it, then boots when other version of windows is selected.  does the same thing on reboot.  also, the front USB3 ports do not work so i feel this motherboard is faulty.

uefi is caching boot records

u may need to clean it

first of all unplug every drive u have connected

then go to bios, go to boot tab and u should see in there something like boot override, select efi shell

u should see command line now

To dump a list of current boot entries:

Shell> bcfg boot dump -v

remove all once by one

To remove the 1st boot option: Shell> bcfg boot rm 0

To remove the 2nd boot option: Shell> bcfg boot rm 1

and so on

once done, power of pc, plug in m.2 and boot from usb install media

try again install win now (with only m.2 + usb pen)

can i also add

make a new usb windows installer using the windows media creation tool

google it

it makes the windows install usb itself and is the very most current version you can use your current windows key

Setup with Clean all Key Boot

 > Secure Boot = Enable Only 

 > CSM = Disable

 > Boot from UEFI Windows manager (Windows 10) 

Hope this will help