Dual Boot Windows 10

[MubashirAzhar]

Dual Boot - No Grub / option to select Ubuntu at boot time, Windows 10 forces itself over Ubuntu

[MubashirAzhar · Accepted solution]

So I did not find help anywhere so I decided to post here, might help others:

 Cannot boot into Ubuntu after installation:

Try hitting F9 at boot time, you will be given an option to boot into Ubuntu if its installed.

If you are looking for a permenent solution and do not want to hit F9 everytime:

1. Hit F10 to enter bios at boot time:

     a. Goto System Configuration

     b. Enable Legacy Support

     c. Disable Secure Boot

     d. Set Legacy Boot Order as desired

2. Hit F9 at boot time and enter Ubuntu, open terminal and enter the following command:     

sudo efibootmgr

The efibootmgr command gives you options to manipulate the EFI Boot Manager.

From the man page:

· BootCurrent - the boot entry used to start the currently running system
· BootOrder - the boot order as would appear in the boot manager.  The boot manager tries to boot the first active entry in this list.  If unsuccessful, it tries the next entry, and so on.
· BootNext - the boot entry which is scheduled to be run on next boot.  This supercedes BootOrder for one boot only, and is deleted by the boot manager after first use.  This  allows  you  to
                change the next boot behavior without changing BootOrder.
· Timeout - the time in seconds between when the boot manager appears on the screen until when it automatically chooses the startup value from BootNext or BootOrder.
· Five boot entries (0000 - 0004), along with the active/inactive flag (* means active) and the name displayed on the screen.

It gives information about current boot (what OS you are booted into), boot order and Timeout. BootOrder is what we are looking for.

Example output:

xxxxxx@HP-Pavilion-Sleekbook-15-PC:~$ sudo efibootmgr
BootCurrent: 0000
Timeout: 10 seconds
BootOrder: 3003,3000,3001,2001,2002,2003
Boot0000* ubuntu
Boot0001* Ubuntu
Boot0002* Notebook Hard Drive
Boot0003  Windows Boot Manager
Boot2001* USB Drive (UEFI)
Boot3000* Internal Hard Disk or Solid State Disk
Boot3001* Internal Hard Disk or Solid State Disk
Boot3003* Internal Hard Disk or Solid State Disk
Boot3004* Internal Hard Disk or Solid State Disk

The left coloum is the boot number assinged, ex: my Ubuntu is assinged Boot0000 where 0000 is the hex number we need for the following step.

3. Having the informantion now enter the following command to change the boot order:

sudo efibootmgr -o 2001,0000,0001,0002

     This should change the boot order. Here 2001 is my USB, 0000 & 0001 my Ubuntu

NOTE: YOU WIlL HAVE TO CHANGE THE NUMBERS TO REFLECT WHAT YOUR OUTPUT IS

4. Even after this I found windows taking over Ubuntu so I deactivated windows by

sudo efibootmgr -A 0003

The * after bootnum indicates it is active. Afer deactivation you should see no *.

Now reboot and you should be booted into GRUB.