Few months back I ran into a situation where i completely destroyed my boot partition of windows trying to multi-boot windows and ubuntu. this situation made me visit the DELL Service center. it was fairly easy for them to fix the system and I got my system back in no time.


  1. Windows installed on 128GB SSD in UEFI mode


  1. Windows was installed on the same 128 GB SSD but in legacy mode.


To setup a multi-boot system where I should not be prompted by GRUB Boot-loader. I achieved this scenario where the windows was installed on the UEFI option and i was able to install the UBUNTU on the legacy mode of the bios. so whenever i had to run Windows i would just enable the UEFI mode and vice-versa.


How should i achieve the same configuration when my windows installation is now installed in the legacy option.

I am unable to enable secure boot and UEFI from the BIOS as it says no UEFI Partition found.



  • Are you open to creating a UEFI partition and reinstalling Windows in UEFI mode? Cause that's probably the best option. – wjandrea Oct 4 '18 at 2:19
  • i am very much open to that i just dont want to screw my windows activation and the partition table in the process – Armaan Farshori Oct 4 '18 at 2:20
  • Well Windows activation is outside the scope of this site. You'd have to ask on Super User instead. – wjandrea Oct 4 '18 at 2:24
  • Dell did not comply with Microsoft requirements. All new systems with Windows 8 or 10 are supposed to be UEFI. And UEFI only boots from gpt, and BIOS only boots from MBR. lf you switch you will erase drive. Also Windows product key for UEFI systems is in UEFI, but only for OEM version of Windows. – oldfred Oct 4 '18 at 3:28

Detailed answer to this question is here.

  1. Create an Ubuntu bootable USB.

  2. Enter the BIOS setup utility.

  3. Select UEFI boot mode.
  4. Plug in the USB flash drive, restart the computer, and press the F12 key or the dedicated boot menu key for your computer.
  5. Find the USB name and press Enter.
  6. You should boot into the Ubuntu installer now.
  7. Start the Ubuntu installation process.
  8. Once on the partitioning screen of the Ubuntu installer, create a swap partition and a root partition.
  9. The most important one is to select the efi-boot partition, say about 100MB. To successfully install on the UEFI mode. Refer to the below screenshot.

    enter image description here

The solution to my problem was fairly easy. I just had to add another partition /boot/efi to successfully install Ubuntu 18.04 on my computer, where Windows 10 was installed on the 128GB SSD in Legacy mode and Ubuntu 18.04 was installed on the 100GB partition of the 1TB HDD in UEFI mode.

Now whenever I want to run Windows 10, I just enable Legacy boot option form my BIOS. Whenever I want to run Ubuntu 18.04, I just Enable UEFI boot option from the BIOS.

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I have faced this kind of problems before, and found a solution. First, IF your computer as you mention supports / uefi/legacy then you are all set.

If you look closely when you install windows or ubuntu from the usb, after you select the boot decies, you know the list of boot devices after pressing i think its F12 for dell computer, you can see for example:

  • CD rom whatever...
  • seagate hard drive xxxx
  • Kingston usb ubuntu
  • UEFI Kingston usb ubuntu


that was the HUGE mess i was doing! i hope i can explain myself. IF you installed Windows 10 in UEFI mode (this is simple to know, when you install in uefi you ALWAYS get 4 partitions on your hard drive) if you installed in Legacy you only get 2 partitions, a fixed one of around 500mb and the "big one"

IF your windows 10 is installaed in uefi, you have to select the "* UEFI Kingston usb ubuntu" so ubuntu will install in uefi, if you select the "* Kingston usb ubuntu" ubuntu will run in legacy and will never appear on your grub menu.

Windows 10 saves your licence number based on your motherboard, so i suggest you BACKUP ALL YOUR DATA, write down which version of windows 10 you have (home, home single languaje, education, pro, etc) download a windows 10 image from microsoft, burn to usb and configure your BIOs to run (preferable) in Legacy mode and secure boot off. Install Windows 10, dont worry , it will self activate (but if asked be sure to select the right version you have, altough the serial nombre of windows 8 / 10 is already written in your motherboard, so usually you are not even asked to select which edition you have, it self detects it). After that now boot the usb ubuntu installation with the proper one selected, the "just plain kingston for legacy, or the "uefi kingston" they are the SAME usb drive, but the bios is letting you choose in which mode you want it to run.

I use rufus to write the ubuntu image to the usb drive.

Good Luck!

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