Completely new to Linux. I tried installing Ubuntu with Windows 10 choosing the installation option for Ubuntu to dual-boot alongside Windows Boot Manager. The installation ran smoothly and I restarted my computer. It restarted and booted Windows 10. I tried many times at it still kept booting up Windows. I also tried Boot-Repair and doing a fresh reinstall. Nothing works. When I start-up my computer, it says 'Reboot and select proper boot device.' The only way i can use my computer is if I boot a LiveCD and choose the 'Try Ubuntu' option. How do I get my computer to boot Windows/Ubuntu?

Boot-info: http://paste.ubuntu.com/12068275 http://paste.ubuntu.com/12068489

  • Do you use grub loader ?
    – orvi
    Aug 14, 2015 at 0:29
  • UPDATE:Thanks for all the help! I was able return to Windows using Boot-Repair. I used EasyBCD to add my main Ubuntu partition to the boot manager, but I still can't access Ubuntu. When I choose the Ubuntu option in the boot manager, it says that I need a Windows Installation CD and gives me an error code.
    – Alex F
    Aug 14, 2015 at 17:52
  • File:/NST/nst_linux-91EE3A857E294D0160B334.... .mbr
    – Alex F
    Aug 14, 2015 at 17:54
  • Load into Windows open command prompt (terminal) and type: powercfg /h off and reboot
    – DnrDevil
    Jan 13, 2016 at 18:55
  • Is ur laptop or PC of HP?
    – minigeek
    Oct 6, 2016 at 7:36

8 Answers 8


I had the exact same problem and tried everything you did too. Finally this is what helped. I opened CommandPrompt as administrator and ran the following:

bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi

Hope that helps.

  • This gives The set command specified is not valid. Run "bcdedit /?" for command line assistance. The parameter is incorrect. Dec 28, 2016 at 4:50
  • If the above solution does not help, enter the boot menu of your bios and set the Ubuntu bootloader in the list to the highest priority, i.e. shift it to #1. That helped out a friend of mine with the exact same problem. Apr 9, 2017 at 1:16

You have to do two things:

  1. Disable secure boot in Windows, instructions here:


  1. Make Windows run in LEGACY mode (select boot mode as Legacy from boot menu)

If you windows fail to start while switching to legacy mode, then you have to reinstall windows to make it run in legacy mode, otherwise Ubuntu will create problems in UEFI mode.

  • 2
    Ubuntu can run in UEFI mode very well, there's no reason to reinstall Windows.
    – Byte Commander
    Jul 24, 2016 at 16:09

boot repair use 2nd option after booting with Live CD

this post might help you


try repair GRUB the graphical way then restart

otherwise, boot the Ubuntu install CD/USB then start to 'install' Ubuntu (yes, you previously installed it but just read on) then your existing Ubuntu OS should be detected - pay ATTENTION at the partition / format screen - refer here then 'reinstall'


Check to see if your motherboard has a boot device option. I have legacy motherboard - Gigabyte H67MA-D2H B3. I installed Ubuntu in dual boot but on seperate HDD. Pressing F12 during boot, brings up an option to select the Boot Device listing installed HDD's etc. Select HDD where Ubuntu is installed and it will boot it.


Found a better workaround. Just go to the boot menu in your bios and and set the "Ubuntu" bootloader to #1 priority(i.e. move it up the list of boot devices till it reaches the #1 in the list). Save the settings and exit. It should boot Ubuntu now or more likely show you the GRUB menu. If in the GRUB menu your Windows 10/8 bootloader is not listed(highly unlikely), don't panic. Just boot into Ubuntu, open the terminal and run

sudo update-grub

This is what my system shows: terminal It should list the Windows 10/8 bootloader in the GRUB menu now. Hope that helps.

P.S. This workaround only works if you have ONLY ONE HDD/SSD on your machine.


You have to go into your uefi/bios settings and either enable legacy boot or disable secure boot, or both. I had the same problem and mixing random settings in there fixed it.


Who manufactures your PC, if it has an OS Manager then you will have a lot of problems like me. this is because the Boot-loader for windows is set as first option in the OS Manager and will automatically boot if present.I have not found anyway to change that. but I did do the boot-repair and it fixed the issue by changing the bootloader.efi to the Ubuntu shim64.efi {grub}.

after this the OS manager will no longer work but the grub offers the boot options. Note the boot-repair must be installed on the hdd not on an external boot media. because it need to write and compile the files prior to recreating the bootloader.efi.

Now that I have it working with Dual boot I will have to change it so it uses the internal ssd for the boot loader. so I will make screen shots of this.


I have a similar problem. Ubuntu 14.04 was installed properly, seen at the shrinked hard disk for windows 10. I found i could boot into ubuntu after booting into windows 10 by going to settings --> system recovery --> advanced options --> reboot the system now. Then you should have an option to do a recovery from usb, there i found ubuntu and was able to boot into ubuntu. Now i'm going to try to get grub working through this articles: Windows 10 upgrade kills grub and boot-repair doesn't help and How can I repair grub? (How to get Ubuntu back after installing Windows?)

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