After installing Qubes I entered the boot menu I found this device “Windows Boot Manager ‘(some code between this brackets that is exactly as the main drive named Qubes OS)’”
I deleted all windows partions during the installation anly kept the EFI system partion.
What this might be? and is it normal to exist after completly removing Windows?
It’s been a while since I had a native Windows installation – but I’m pretty sure that the “Windows Boot Manager” is stored on an EFI partition. So if you kept the EFI partition (and didn’t format it), I’m not surprised that it still contain the files for Windows Recovery … nor that Windows Recovery has trouble locating the partitions it would like to boot from …
If you want to dual/multi boot the machine, then a format of the EFI partition will make the previous Operating System(s) non-bootable and only allow you to boot the latest OS you have installed.
If you only want to run a single OS on the machine, then it should safe to format the EFI partition during installation - since you don’t care about booting the previous OS(s).
The EFI partition is just a file system with files - you won’t need to format it, just to delete files.
I would recommend/suggest
a backup of the files on the EFI partition
an USB stick with a live Linux OS you can boot and use to recover
use mv to renamme files/folders (so it’s easy to restore, if it breaks)
To find candidates, you can try to run:
for f in `sudo find /boot/efi`; do
sudo rpm -qf ${f}
done | grep 'not owned'
– but note that some of the files on the list, might be needed by Qubes OS … but you’ll probably see a folder for Windows …
A full re-install (with a format of the EFI partitions) is a big hammer - but will also work … and if it’s a fresh installation, it might also be simpler.