Dual Booting Windows 10 and Ubuntu but can't select OS at boot

Question

So I finally got Ubuntu installed on my laptop, but the computer still automatically boots to Windows 10 instead without asking me first. I can still access Ubuntu through UEFI, but the only way I can consistently do that on my computer is to take out the battery and hold down the power button for 30 seconds to get the "press ESC to pause startup" message after booting, which is really annoying to do.

I've tried messing with Windows' settings but it doesn't seem to recognize that Ubuntu's there. The original installation seemed to go fine as well, and GRUB_HIDDEN_TIMEOUT=0 is commented. So what's the issue here and how can I go about fixing it?

Solution 1

The symptoms you report can be caused by at least three things:

• Mixed-mode (BIOS/EFI) installations -- If Windows is installed in EFI mode and you install Linux in BIOS/CSM/legacy mode (or vice-versa), you can see something like what you report. The best solution to this problem is to install an EFI-mode boot loader for Linux. The Boot Repair tool recommended by others can do this, and there are other ways to do it, too; however, it's important that you verify that this is the problem before you try this fix. Also, Boot Repair will do nothing useful if you run it from a BIOS-mode boot, so you must disable your CSM before you attempt this repair. See my page on the CSM and its problems for more on this issue. You can tell if your Ubuntu is booting in EFI mode or in BIOS mode by looking for a directory called /sys/firmware/efi. If that directory is present, you've booted in EFI mode and this explanation is most likely not the issue; but if that directory is not present, you've booted in BIOS mode and this may well be the problem.
• Mis-set EFI-mode boot order -- On an EFI-based computer, the order in which the computer tries various boot loaders is stored in NVRAM. If this information is incorrect or missing, you can end up booting straight to the wrong OS. To fix it, you can adjust the boot order with efibootmgr, as described here; or in Windows with the EasyUEFI utility.
• Windows adjusting the boot order on every boot -- This possibility is a special case of the former one. I've seen some reports of Windows adjusting the boot order with every boot. This can result in something like the problem you're seeing, but with the caveat that the boot order remains set to Ubuntu if you shut down or reboot from Ubuntu, but it changes only when you boot to Windows. See this question and answers for more on this problem.

Because the solutions are so different, it's important that you better diagnose the problem before proceeding. Checking your Ubuntu boot mode is the most important diagnostic. Identifying whether the problem occurs with every boot or only after booting to Windows is also important.

Finally, most EFIs provide some means to enter a built-in boot manager; however, this option is sometimes disabled by a firmware "fast start" option. Try entering your firmware setup utility and looking for any option called "fast start" or something similar and disabling it. This feature causes the firmware to perform minimal USB initialization rather than full USB initialization, so the keyboard may be non-functional until an OS takes control. Sometimes it's referred to as something relating to USB initialization, so you can look for options like that, too.

Solution 2

Enter your terminal by pressing ctrl+alt+t to open your terminal and type

sudo update-grub

After that you will see on the last line your other OS name then Done after that restart your system.

Comments

[Admin]

Do you have Secure Boot disabled in the BIOS? You may also want to check whether your BIOS settings allow you to choose the UEFI boot order (this is not the boot device order).

[Admin]

You can solve this using the boot repair. I am attaching a link below try trying this out This is the link fo bootrepair Please use the Live os of ubuntu and follow the process listed in the site

[Admin]

What brand/model system? And did you install Ubuntu in UEFI boot mode? May be best to review details of your install from Boot-Repair's summary report before attempting any fix.

[Admin]

Try to login into Ubuntu Linux and try boot-repair. Otherwise another quick fix(agree to what Zacharee1 said)...login into Windows 10 and then try this "type the following command in an admin command prompt: bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi"

[Admin]

Secure Boot is almost certainly not the problem; if it were an issue, no Ubuntu boot would work, including the Ubuntu installer.

[Nick Dewitte]

When using the EasyUEFI tool, but windows keeps changing the order, I found it a solution to disable the "Windows Boot Manager" entry. This forces the UEFI to pick the (in my case openSUSE) bootloader, which offers a choice with a link back to windows as one of it's options. Might be worth noting that this could be dangerous since it can't automatically boot to windows once your Linux distribution is removed again. This might or might not be solved by manually selecting the bootloader for windows, where you can re-enable the windows boot manager afterwards.