Optiplex 3070 unable to boot Windows 10 from internal HDD.

3070 what? MT, SFF, Micro, gen 9 dell, whoo whoo...

as you can see at dell.com there is manual all 3 PCs, they are not the same really.

with M.2 storage , gumstick ssd.

boot order is?

are you using UEFI ? or not, secure boot?>  this is first thing. id turn it off and run just GPT drive.

the windows install just let it load to and empty drive, do not play with partitions, let it do it's job, ok?

name all ports the drives are connected which sata ports exactly.

the blue jack is most times the boot port sata. blue.

my first guess is  you did not erase the  media first

you can also remove all drives not needed to boot before you install preventing the wild and wrong erasure of other disk loaded with MKV movies lets say.

windows hates any disk no empty,  for many reasons and now more (UEFI sacred)

it does not understand over 100 formats possible and will balk at data random.

if i get in trouble, say using some found apple disk (alien no?) I run killdisk.exe free and linux is alien too.

just alien to setup.exe.

install using MS built v1903 USB made from ISO, using MS builder, ok? just that.

m.2 in m.2 SSD  slot not the M.2 wifi slot.

this PC has new BOOT manager, so you need to deal with that for boots to work, ID turn off all that. no UEFI and legacy boots on.

did this PC come new as Ubuntu as dell support page shows?

No bootable device found is due to drive that must be cleared using DISKPART and reinstalled with USB2 media. Secure Boot off,  F12 boot from DVD,  Sata Operation Set to AHCI,  Boot mode UEFI.  Drives will have to be removed and then boot modes in bios cleared.  Then Just hard drive reinstalled, cleared, then os put on.  BIOS is not a boot manager for dual boot of multi os.  

https://www.bestbuy.com/site/lg-8x-external-usb-2-0-blu-ray-disc-double-layer-dvdrw-cd-rw-disc-rewriter-black/9243009.p?skuId=9243009

https://www.newegg.com/microsoft-windows-10-pro-64-bit-reinstall-recovery-disc-only-no-license-key-included/p/N82E16832350238

Reimage Guide for Windows 10 Optiplex 3070

https://downloads.dell.com/manuals/all-products/esuprt_desktop/esuprt_optiplex_desktop/optiplex-3070-desktop_user%27s-guide_en-us.pdf

https://insights.adaptiva.com/2017/configmgr-geeks-guide-mbr2gpt-exe-tool/

Transfor to GPT after installation from USB

Hi Team,

The same issue happening with me also, but we have only one 1TB drive in our system.

Nothing coming in diagnostic, after successfully installed OS and after restarting it's saying no bootable device found (not booting from HDD).

Can you please help me to resolve it.

Thanks in Advance.

Did you resolve this?, I also have the same problem