… but of course it does - I have done it at least a hundred times … 
You created an MBR/MSDOS based Manjaro installer, and you needed to have created one that booted as UEFI.
That’s what you did
You cannot install Manjaro as UEFI using that USB. 
You should create a new Installer USB that boots as UEFI
I understand you may have some difficulty creating a workable USB installer, but it is what it is.
Further to this, the 25.0.9 ISOs were broken – something that impacted their ability to boot – I followed another thread briefly while @philm worked to resolve the issue, and the new 25.0.10 ISOs were released yesterday to correct the problem.
This may or may not be a factor in your issues, but the incorrect type of Installer USB certainly is.
Did you input this? This would be trying to perform a Legacy installation but you are on EFI?
it looks like sda1 is EFI, no ?
i don’t really know what i’m doing that’s why i post the command lines i’m doing…
what is the command line i must write ?
I tried that already in a previous post.
As explained, the USB Installer does not boot as UEFI. It must boot as UEFI to install properly to a UEFI system.
It “seems to work” because it’s installed in Legacy Mode – because your USB has not been prepared to boot as UEFI – your USB must boot as UEFI to install as UEFI.
This can be set before you create an Installer USB, presuming you use Rufus to create it.
Alternatively, you can create a Ventoy USB (see above), and the same thing will apply – you must change the configuration (in Ventoy) before creating a Ventoy USB.
The 25.0.10 may be helpful.
Again – The USB must be created to boot as EUFI.
Has that much sunk in yet? 
Do you like lists?
- Borrow someone elses computer if needed
- Download the 25.0.10 Manjaro ISO
- Download either Rufus or Ventoy and run it.
- Configure Rufus (or Ventoy) to create a UEFI booting USB
- Create the USB
- Boot your system with it.
Viola!
You are asking how to chroot into your system?
Boot from the installation medium, open a terminal, issue the command
manjaro-chroot -a
This should work when you used ext4 as the file system when installing.
It’s a bit more involved when you chose to use the (now default) BTRFS.
I suggest Ventoy.
Scroll up to find the link I gave for a tutorial.
Again, read my last post.
manjaro-chroot -a ✔
grub-probe: error: cannot find a GRUB drive for /dev/sdb1. Check your device.map.
grub-probe: error: cannot find a GRUB drive for /dev/sdb1. Check your device.map.
==> Mounting (ManjaroLinux) [/dev/sda2]
--> mount: [/mnt]
--> mount: [/mnt/boot/efi]
[manjaro /]#
… yes - this is what a successful chroot using that command looks like
thank you
first time working
every other command lines about chroot i copied failed
(i don’t create or imagine command lines)
Since the topic is a bit of a mess, did someone mentioned to check the firmware settings? It has to be selected uefi only boot mode, no csm, no bios, no legacy.
Otherwise, the above chroot looks good despite the errors. Now if we assume we have a uefi live usb booted as uefi (you can check if the directory /sys/firmware/efi/efivars exists then you are good),
Go back to the grub restore tutorial and this time use the efi variation of the command without copy paste errors 
like the word root and without sudo (chroot is already root, that is what # stands for)
i don’t know what you’re talking about, sorry
but thank you
I’m stepping away from this conversation for sanity sake.
I’ll simply say… good luck.
obviously manjaro is about luck…
thank you for your help
No, not really. Rather there are two incompatible ways of booting. The old BIOS (or Legacy) way and a successor called (U)EFI. You need to stay inside one booting method. Please check your BIOS setting whether it is on Legacy or EFI. Then accordingly create a USB stick installer - seems currently the installer is created for Legacy but you try to perform an EFI installation with it, hence it fails.
I don’t think there is much with Manjaro related here. Other distro installers will also fail if one mixes up the booting method between Legacy and EFI. The only thing one could question is why the installer says “success” if it can’t boot. But perhaps this kind of mix up can’t be detected beforehand?
My bios is UEFI. It’s not the first time i install a distribution on it (or on other uefi computers).
I don’t remember which app i took to burn the iso. I think it was Unetbootin…
The only thing one could question is why the installer says “success” if it can’t boot. But perhaps this kind of mix up can’t be detected beforehand?
I agree with you ! We’ve just lost a lot of energy…
Thank you for your help 
I’ll come back after the installation (and boot) is ok.
Hi !I don’t have another computer (or a friend near me) to build another manjaro live usb on my 64Go usb - but i have a 1Go usb key so i tried something : i downloaded a minimal ubuntu (Ubuntu 18.04 “Bionic Beaver”) to make a clean installation with this 1go so that i can rebuild my manjaro live usb from this newly ubuntu installed. Please tell me if this idea doesn’t make sense. I format the usb in ext4 with gparted, built the key with Ventoy. Reboot on the Ventoy tiny Ubuntu 1 Go usb + installation complete. Rapid start boot & Secure boot disabled with UEFI - It doesn’t work either.
~ sudo fdisk -l ✔
Disk /dev/sda: 111,79 GiB, 120034123776 bytes, 234441648 sectors
Disk model: XrayDisk 120GB
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 313AFB47-5EE7-40FB-9B82-CF42151C295A
Device Start End Sectors Size Type
/dev/sda1 2048 1050623 1048576 512M EFI System
/dev/sda2 1050624 234440703 233390080 111,3G Linux filesystem
Disk /dev/sdb: 59,16 GiB, 63518539776 bytes, 124059648 sectors
Disk model: Cruzer Glide 3.0
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000
Device Boot Start End Sectors Size Id Type
/dev/sdb1 * 64 9812411 9812348 4,7G 0 Empty
/dev/sdb2 9812412 9820603 8192 4M ef EFI (FAT-12/16/32)
Disk /dev/loop0: 60,62 MiB, 63565824 bytes, 124152 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop1: 2,16 GiB, 2319208448 bytes, 4529704 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop2: 1,41 GiB, 1512828928 bytes, 2954744 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop3: 928,31 MiB, 973402112 bytes, 1901176 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/sdc: 965 MiB, 1011875840 bytes, 1976320 sectors
Disk model: USB Flash Disk
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x86a1ebd2
Device Boot Start End Sectors Size Id Type
/dev/sdc1 * 2048 1910783 1908736 932M 7 HPFS/NTFS/exFAT
/dev/sdc2 1910784 1976319 65536 32M ef EFI (FAT-12/16/32)
~ manjaro-chroot -a ✔
grub-probe: error: cannot find a GRUB drive for /dev/sdb1. Check your device.map.
grub-probe: error: cannot find a GRUB drive for /dev/sdb1. Check your device.map.
==> Mounting (Ubuntu) [/dev/sda2]
--> mount: [/mnt]
--> mount: [/mnt/boot/efi]
root@manjaro:/#
What’s the problem ?
As far as I can see, you have no data to lose. Have you tried resetting your firmware to factory settings?
Have you always checked the checksum of the ISO after placing it onto the USB key?
Also, try to find a way to do this, afterwards:
Indeed, it makes perfect sense.
Could you elaborate a little?
- How does it not work?
- Does Ubuntu finish install and then not boot?
- Does the Ubuntu USB not boot? Does it stop at a certain point? What point, exactly?
Details please!
It is also possible that your USB is damaged. 