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Sorry for my bad English. I converted my disk from gpt to mbr to reinstall window 10 in my laptop (acer) with a usb boot yesterday, and i changed bios from uefi to legacy too. I suceed. After that, i started my laptop and it had a black screen with "exting PXE rom" but my laptop still work nomally. I searched google for the cause. Then, I used the usb boot to change the disk from mbr to gpt and i change bios from legacy to uefi, hope it will solve the problem. After that my laptop has "no bootable device" screen. I decided to change the disk back to mbr, and changed bios to legacy then my laptop had black screen with "No bootable device – insert boot disk and press any key". I coundn't open the boot menu with F12 button too. Please help me, and sorry for my bad English
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Hello again.
Forgive the delay.
You should be able to access the Bios by pressing the F2 key and be able to boot the USB drive as the first option.
How did you manage to do it before?
The conversion can be done from the Diskpart command in the Command Prompt.
You can also enter the Recovery Environment by forcing a shutdown 3 times during the PC startup.
Greetings.
start installing from win10-cd, then chose "repair pc"
do not install fully!
go to cmd:
system32>bootsect /nt60 c: /mbr (important: do not forget space!)
I had the same problem as you have, but with GPT
There are many causes for this, for me the problem was a blank partition had been created probably during a Windows install and it was before UFI partition. My Windows would boot on second run but randomly would give the no bootable device found. However to sort the problem out I had to use a 3rd party software that allowed me to move partitions without the loss of data which worked.
