GRUB Doesn’t detect windows: Disk is MBR but booting via UEFI

I dun goofed. I thought my Windows was booting using UEFI, and I installed Ubuntu using UEFI. But now I think my Windows was booting using MBR, and GRUB can’t detect it.

I’m confident the disk is MBR:

> sudo gdisk -l /dev/sdb GPT fdisk (gdisk) version 1.0.3  Partition table scan:   MBR: MBR only   BSD: not present   APM: not present   GPT: not present 

and that I’m booting via UEFI:

> ls /sys/firmware/efi/ config_table  fw_platform_size  runtime      systab efivars       fw_vendor         runtime-map  vars 

How can I fix my GRUB so that it boots using MBR instead of UEFI?

I’ve tried:

  • Running os-prober and update-grub
  • Running boot-repair

Neither gave me a GRUB menu with Windows listed.

How can I change the plymouth booting animation on Ubuntu 19.04?

I have downloaded a Plymouth theme from And since it was a deb package, I installed it through Ubuntu Software. Then, I typed “sudo update-alternatives –config default.plymouth” and selected the newly added theme. But it didn’t work out at all, and Plymouth theme didn’t change. If you know how to do it properly, please let me know. Thanks.

Cannot use ps2 keyboard during booting and in grub but works fine after os is loaded

A few days ago I installed and updated UBUNTU to it latest version during that period my keyboard worked fine in bios. And now I can’t boot to windows due to keyboard not working in grub. I tried removing CMOS battery but no difference. Also tried usb keyboard but same result. Pls help. AND THANKS IN ADVANCE.

boot-repair it not detecting windows and hence no grub menu item for booting windows

I have problems getting kubuntu installed and dual boot together with windows 10. I have two disks one for windows and one kubuntu. I would like to have grub installed on the kubuntu disk and have it dual the windows.

Boot-repair gives this output:

I have tried the os-prober, grub update and boot-repair but none of them gives a installation that produces a grub menu item to boot windows. If I change my bios to boot the windows disk it works fine. Booting the ubuntu goes fine from the disk with grub/kubuntu.

It looks like I need the boot-repair to find my windows installation before I can get this to work. But how?

When i am booting my Centos server Stuck on grub prompt

I have a server on OVH with Cpanel which has 2x2TB partition and its lsblk command output looks like this. Few days back I ran some upgrades and after reboot my server didn’t boot properly and it halts during boot process and gave prompt like this:

I did some RnD and I was able to boot the server by running following commands on grub prompt:

set prefix=(hd0,gpt2)/boot/grub2 set root=(hd0,gpt2) linux (hd0,gpt2)/boot/vmlinuz-4...…… root=/dev/md2 ro boot 

Then I searched for its permanent solution which takes me to some URLs like this which suggest to reinstall grub using commands:

# update-grub # grub2-install /dev/sda 

I am on Centos which doesn’t has command:update-grub but I was able to run other command:

[root@server2 ~]# grub2-install /dev/sdb Installing for i386-pc platform. Installation finished. No error reported. 

after this Upon reboot I again got the same grub prompt.I am not sure what is wrong here. Can anyone please suggest something.

Dual Booting installation fails, leaves residual Ubuntu boot option, upon booting from it encounter GNU Grub menu

I have Windows 10 installed already, and am trying to dual-boot with Ubuntu desktop(19.04). However, after finishing the dual-boot installation (allocating memory), Ubuntu asked for a restart, and upon restarting, my screen was filled with “squashfs” errors. After a long period of waiting, I decided to force shutdown. After turning my computer on from the shutdown, there was no Ubuntu dual-boot menu, and Windows was immediately booted. I decided to go to Window’s disk management application (diskmgmt.msc) to delete the memory I allocated to my failed Ubuntu installation, and reattempt to install Ubuntu. However, when I am on the advanced startup page to attempt to boot from my USB to reinstall Windows, there is still an option to boot from Ubuntu, even though I already deleted the partition containing it. When I attempt to boot from it, (can also be accessed from default boot menu upon computer startup), I am greeted with this GNU Grub shell. Can anyone direct me on what I should do?