Hello everyone I am having trouble with my Mate desktop I’m getting the following message when I try booting my system
error : no such device: 28854a41-8f1f-4841-b4ca-1b3afeaa625c.
Entering rescue mode…
Anyone have any idea how I can correct this
Thanks so much
It initially appears that grub can’t find a partition identified by a UUID.
(error : no such device: 28854a41-8f1f-4841-b4ca-1b3afeaa625c)
What do you wind up seeing on your screen? A blinking cursor? A totally blank screen? busybox? grub rescue?
If grub rescue, then take a look at this -
And this too -
Reinstalling grub usually fixes these sorts of things. Good luck Robgoss.
And some more…
I’ve found that this instruction is the best when you need to recover grub.
And if you have a UEFI bios, see -
When you install Windows, Windows assumes it’s the only OS on the machine–or at least it doesn’t account for Linux. So, it replaces grub with its own boot loader. What you have to do is replace the Windows boot loader with grub. I’ve seen various instructions for replacing grub by mucking around with grub commands or some such, but to me the easiest way is to simply chroot into your install and run grub-install and update-grub. chroot is great because it allows you to work on your actual install, instead of trying to redirect things here and there. It’s really clean.
Sometimes giving GRUB2 the correct configuration for your partitions is not enough, and you must actually install it (or reinstall it) to the Master Boot Record.
Here’s how:
Boot from a live USB.
Determine the partition number of your main (root) partition. GParted can help you here. I’m going to assume in this answer that it’s /dev/sda6, but make sure you use the correct partition number for your system! Look to see which drive grub uses to boot from. Check for a boot flag.
Mount your partition:
sudo mount /dev/sda6 /mnt
make sure that sda whatever is correct!
Bind mount some other necessary stuff:
for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt$i"; done
chroot into your Ubuntu install:
sudo chroot /mnt
At this point, you’re in your install, not the live CD, and running as root. Install grub:
grub-install /dev/sda
make sure that this is the correct (bootable) HD! Gparted will label the boot partition.
Update grub:
update-grub
If everything worked without errors, then you’re all set:
exit
At this point, you should be able to reboot normally.
Hi @Robgoss,
boot the live Ubuntu Mate CD and open Welcome and it’s under Installation Help → Dual Booting > Boot Repair. 
This is not a dual boot just mate on this machine
Thanks everyone I managed to run the boot repair and reinstalled the grub boot loader this is the first time having to use it. I was trying to install Kubuntu on a external hard drive when I lost my boot loader
Big thanks to you all
Hi @Robgoss,
it doesn’t matter whether you dual boot or don’t, Boot Repair will still do its job!. Glad you are sorted!. 
Thanks for the hint about the Welcome. I’ve take a look in “Welcome” again and found a lot of unknowed things like
Good Work! 