Hi,

In case you’ve a dual boot machine, sometimes it might happen that grub menu is no longer appearing.

For systems using regular BIOS, a grub-install against the device it was installed might be required, but when using UEFI, it’s really easy to use a rescue media and execute efibootmgr to alter the boot order.

When executing efibootmgr, it might output some information like this:

BootCurrent: 0001
Timeout: 0 seconds
BootOrder: 0001,0019,001D,001C,0017,0018,001A,001B,001E,001F,0020,0000
Boot0000* Windows Boot Manager
Boot0001* Fedora
Boot0010  Setup
Boot0011  Boot Menu
Boot0012  Diagnostic Splash Screen
Boot0013  Lenovo Diagnostics
Boot0014  Startup Interrupt Menu
Boot0015  Rescue and Recovery
Boot0016  MEBx Hot Key
Boot0017* USB CD
Boot0018* USB FDD
Boot0019* NVMe0
Boot001A* NVMe1
Boot001B* ATA HDD2
Boot001C* ATA HDD3
Boot001D* ATA HDD0
Boot001E* ATA HDD1
Boot001F* USB HDD
Boot0020* PCI LAN
Boot0021* IDER BOOT CDROM
Boot0022* IDER BOOT Floppy
Boot0023* ATA HDD
Boot0024* ATAPI CD

Note there, the BootCurrent and the BootOrder, the numbers in the BootOrder correspond to the Boot#### that are listed below it.

Once we’re sure about the boot order we want (for example, to restore booting into grub), execute:

efibootmgr -o 0001,0000,0010,0011

But, choosing the right order you want for your system.

Enjoy! (and if you do, you can Buy Me a Coffee )