BootDevice Not Found - acer aspire s7

[Şerban S.]

Hi!

[...] When i restart it without they key, i have a black screen with the mention "BootDevice Not Found"[...]
UEFI is enabled
secure boot is disabled [...]

This message means at least two things:
1. The destination drive is damaged. This means it has bad sectors.
2. The drive has an MSDOS type partition. This always leads to errors since your machine has UEFI firmware.
In either case, you need to diagnose the disk.
For that, you need a tool that does that.
The tool is called GPartEd Live, meaning that you have to go to the site, download the ISO image, burn it on an USB stick, then boot it.

https://gparted.org/livecd.php

Download:

https://gparted.org/download.php


After the booting process finishes, you will be in front of the GPartEd window.
It will tell you about the drive's partitions, types, sizes and the rest.
It will also tell you the type of partition.
Select from the Menu View > Device information.
It can be either "MSDOS" or "GPT" (UEFI, Global Partitioning Table.)
If the drive is MSDOS partitioned, than you have to delete all, until all space says "Unpartitioned" or "Unallocated".
Now choose from the menu Device > Create partition. Choose the GPT type, then "Apply".
If you know how to go from here, than do it. Create and format the partitions, starting with the FAT32 boot partition and then the others.
If you are unfamiliar, then stop the computer, insert the boot drive (Linux Lite) and reinstall, with the default option.
Let the installer do the rest. Just follow the on-screen instructions.

Keep us updated.

Best regards, Șerban.