Extraits du boot-info
1) Boot en mode EFI
===================================== UEFI =====================================
BIOS is EFI-compatible, and is setup in EFI-mode for this installed-session.
SecureBoot enabled.
efibootmgr -v
BootCurrent: 0002
Timeout: 2 seconds
BootOrder: 0002,0000,0001,0003,0004
Boot0000* Windows Boot Manager HD(1,GPT,2bd26b86-af8b-46b1-8643-aab135a4f8dd,0x800,0x82000)/File(\EFI\MICROSOFT\BOOT\BOOTMGFW.EFI)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}....................
Boot0001* UEFI:CD/DVD Drive BBS(129,,0x0)
Boot0002* ubuntu HD(1,GPT,2bd26b86-af8b-46b1-8643-aab135a4f8dd,0x800,0x82000)/File(\EFI\UBUNTU\SHIMX64.EFI)
sda1: __________________________________________________________________________
File system: vfat
Boot sector type: Windows 8/2012: FAT32
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files: /efi/Boot/bootx64.efi /efi/Boot/fbx64.efi
/efi/Boot/mmx64.efi /efi/ubuntu/grubx64.efi
/efi/ubuntu/mmx64.efi /efi/ubuntu/shimx64.efi
/efi/ubuntu/grub.cfg /efi/Microsoft/Boot/bootmgfw.efi
/efi/Microsoft/Boot/bootmgr.efi
/efi/Microsoft/Boot/memtest.efi
2) Les partitions
fdisk -l (filtered): ___________________________________________________________
Disk sda: 238.49 GiB, 256060514304 bytes, 500118192 sectors
Disk identifier: 366E6446-6A50-40A4-83F9-BCBC10C1213E
Start End Sectors Size Type
sda1 2048 534527 532480 260M EFI System
sda2 534528 567295 32768 16M Microsoft reserved
sda3 567296 303042177 302474882 144.2G Microsoft basic data
sda4 498786304 500117503 1331200 650M Windows recovery environment
sda5 303042560 498786303 195743744 93.3G Linux filesystem
Partition table entries are not in disk order.
df (filtered): _________________________________________________________________
Avail Use% Mounted on
sda3 106.6G 26% /mnt/boot-sav/sda3
sda4 237.4M 63% /mnt/boot-sav/sda4
sda5 77.3G 10% /
sda1 est oublié........
3) les points de montage
========================== sda5/etc/fstab (filtered) ===========================
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sda5 during installation
UUID=3d16788b-90f7-4199-9675-940a1941c302 / ext4 errors=remount-ro 0 1
# /boot/efi was on /dev/sda1 during installation
UUID=E497-B76E /boot/efi vfat umask=0077 0 1
/swapfile none swap sw 0 0
Le fait que tu n'aies pas pu créer une partition FAT32 avec l'installateur va rester un mystère