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Dual-boot BIOS legacy UEFI motherboard

alb05 Posted messages 29 Status Member -  
alb05 Posted messages 29 Status Member -

Hello,

I am in the same situation with an Acer X3900 PC Motherboard FIH57 and an American Megatrends Inc BIOS P01-B1 from 03/04/2010 SMBIOS=2.6

The BIOS mode is LEGACY so not UEFI, so no DUAL-BOOT is possible apparently

Since it's an old PC, it struggles at startup with Windows 10 with all these updates and antivirus...

So I would like to see a Dual-boot to also use UBUNTU as an OS.

But this testimony from 2019 seems definitive.

It is impossible to make a motherboard that is not designed for BIOS compatible with UEFI

Can you confirm that I should stop hoping?

Thank you

NB referring to the post :
https://forums.commentcamarche.net/forum/affich-36045124-savoir-si-pc-compatible-uefi

9 answers

  1.
    brucine Posted messages 24834 Registration date   Status Member Last intervention   4 166
     

    Hello,

    The fact that the BIOS is UEFI only allows for the use of the associated Boot Manager; nothing prevents a dual boot via Grub in Legacy mode.

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  2. alb05 Posted messages 29 Status Member
     

    Thank you for this quick response that gives me hope

    I will therefore inform myself about GRUB

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    1. brucine Posted messages 24834 Registration date   Status Member Last intervention   4 166
       

      We used to dual boot ages ago when UEFI didn't exist anymore.

      In principle, the Ubuntu installation routine after Windows has the "intelligence" to recognize Windows and set up Grub accordingly without us having to do anything (the reverse is not true).

      Only if this fails for some reason or another will we be led to edit Grub.

      The prerequisite is, of course, that if we use a USB stick as installation media, it must be created in MBR mode and the BIOS must be configured to be able to boot from this stick.

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  3. alb05 Posted messages 29 Status Member
     

    My Ubuntu install key is indeed in MBR.
    If UEFI is used to manage the Boot Manager, then I understand why the Ubuntu installation does not offer me the option Install Ubuntu alongside Windows Boot Manager

    I had read that it was better to avoid having more than 4 partitions, so I repartitioned an old D: of data to merge it with C: next to the Windows directories. And created a free partition for Ubuntu

    I even turned off the optimized boot (I had read that too)

    And upgraded the BIOS with the latest and old version of the BIOS hoping it would offer me a multi-boot option, but to no avail.

    Since the option to install alongside Windows wasn't available, I did the Ubuntu installation with the only available option, but that's when it got complicated with the need to allocate Swap spaces and other sub-partitions ...

    The installation was carried out on these partitions, but then I got the message "Reboot and select proper boot device or insert boot media..."

    I had to tinker to repair the partitions and Windows to be able to restart.

    There is definitely something I missed and did wrong.

    So now I find myself with a multitude of partitions (see image) and with doubts about being able to coexist with Ubuntu alongside Windows on my old PC!

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    1. brucine Posted messages 24834 Registration date   Status Member Last intervention   4 166
       

      Hello,

      It's normal for Ubuntu to ask to create several Swap partitions and the like, recovery partitions 1 and 5 are normal, and the Ubuntu partition will typically be seen as ext4 by the Linux partition manager.

      The limit of 4 primary partitions on the same physical disk pertains to MBR mode, but your screenshot shows that your system has a UEFI boot partition and a GPT table, so it's all quite confusing.

      Currently, what happens? Does it boot into Windows, Ubuntu, both as a choice, or none?

      If the Ubuntu installation failed, we can just quickly uninstall Ubuntu and start over (while keeping the reserved disk space) but NOT by deleting the partition haphazardly, as that leads to troubles.

      In this context, the only thing left to do is to redo your USB stick, this time in GPT mode (and indeed disable security in the BIOS) and start again: just follow the tutorial with the "alongside" option, the system should dual-boot automatically after the installation finishes.

      The method to properly uninstall Ubuntu if it has somehow been installed is also detailed in a link in this link.

      By the way, I'm not sure that, if the argument is the low performance level of the PC, Ubuntu is a good choice; you might opt for lighter distributions, such as Linux Mint (even in its heavier Cinnamon environment) or anything to your taste as long as the installation routine offers an "alongside" option.

      https://www.malekal.com/installer-ubuntu-22-04-dual-boot-windows-10/

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  4. alb05 Posted messages 29 Status Member
     

    Oops, I realize that I attached the wrong partition file.

    Sorry for the mistake


    Here is the one for the Acer in question with the new USB drive mounted in GPT

    It's not really the same thing !!

    As it stands, it boots directly into Windows

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    1. brucine Posted messages 24834 Registration date   Status Member Last intervention   4 166
       

      Oh dear, this is a mess.

      We have an unallocated partition of 3.37 GB that shouldn't exist and needs to be merged with the adjacent partition to recover its space (which corresponds to the small D: partition in FAT32; what is on it, a boot or recovery partition, but it shouldn't be lettered, probably not Ubuntu?) or otherwise with one of the two 37.25 GB partitions, but the non-contiguity then requires using a dedicated utility (Aomei Partition Assistant or equivalent).

      The existence of Ubuntu on the USB stick along with two identical partitions of 37.25 GB suggests a dual installation of Ubuntu on these partitions or no installation at all: Ubuntu might then only be running in "Live" mode from the USB stick and not installed; we need to check the usage rate of these partitions, but it is likely that if Ubuntu had been installed, its Grub boot sector would have overwritten the Windows one, meaning the system would only boot under Ubuntu or offer dual boot options from Grub.

      An additional way to check is to restart using the quick access key to the BIOS that brings up the Boot Manager; I don’t know which one, it depends on the BIOS, often F2: if there is an installed Ubuntu even if it’s not in the dual boot, it should be present there and we could manually start it from that choice.

      Under these conditions, disk 0 is indeed in Legacy MBR mode, but we need to be consistent: the USB stick must be as well, so it needs to be recreated in MBR mode.

      If the checks, as I think, show no existence of Grub or any Ubuntu installation, we will merge the two 37.25 GB partitions and then restart the correct Ubuntu installation USB stick and follow the linked tutorial, installing Ubuntu "alongside" by specifying, without mistake, this partition (relying on its size).

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  6. alb05 Posted messages 29 Status Member
     

    The H: key is the install key. It is there simply to show on the copy screen that it was in GPT

    Okay, I'm going to remake it in MBR FAT32 with the same ISO

    For the partitions other than the Windows one, I'm ready to break them all and merge

    In fact, originally before the install, I had created an empty 80 GB partition for Ubuntu

    And it was the Ubuntu install that asked me to allocate space twice, so I believe I left the default values which must have been 37.25 GB

    On the D: partition there are Ubuntu files but I don't know what they are!

    But as a result, I'm going to end up in the same situation as before in MBR

    I don't understand what will make the install coexist "beside" it now

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    1. brucine Posted messages 24834 Registration date   Status Member Last intervention   4 166
       

      It is an EFI partition and cannot be bootable since the BIOS is Legacy and the disk is MBR; it likely results from the fact that the USB drive was mistakenly set to GPT; in any case, Grub clearly does not start, and there should normally be no obstacle to deleting it outright.

      As a precaution, edit grub.cfg (notepad) to see if it references Windows, unlikely since if that were the case, it would be in the Boot folder.

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  7. alb05 Posted messages 29 Status Member
     

    grub.cfg :

    search.fs_uuid c935d18d-c210-423a-abd3-3bf3da0396e8 root hd0,msdos5
    set prefix=($root)'/boot/grub'
    configfile $prefix/grub.cfg

    I will therefore delete all these partitions to merge them into a single 80 GB partition.

    Do you then think that with a MBR key like the Windows partition, the Ubuntu installation will offer a "side-by-side" installation mode with Windows?

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    1. brucine Posted messages 24834 Registration date   Status Member Last intervention   4 166
       

      This would be the first time we don't succeed

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  8. alb05 Posted messages 29 Status Member
     

    There you go, I have my key in MBR/FAT32.

    And I've merged the partitions with AOMEI to have just one single unallocated partition of 78 GB that I reserve for Ubuntu.

    Does this starting situation seem right?

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    1. brucine Posted messages 24834 Registration date   Status Member Last intervention   4 166
       

      Yes, if the installation routine recognizes the unallocated space; otherwise, you will need to create a volume and format it to anything, let's say NTFS, anyway Ubuntu will reformat it to ext4.

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  9. alb05 Posted messages 29 Status Member
     

    Okay, I'm going to try it this way. But if it's better to format the partition to D:, can I do that?

    My worry before I jump in is ending up with an install that doesn't offer me "beside" and questions about the size I want to allocate to the different partitions.

    When I did it the first time, the tutorials weren't clear, and as a result, I created two 38 GB partitions.

    Probably a bit excessive for swap, but not knowing, I'm still left wondering.

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    1. brucine Posted messages 24834 Registration date   Status Member Last intervention   4 166
       

      I don't know, I haven't done it in a long time; if the installation routine doesn't offer to install in the right space, we abandon it, nothing will be done, and we start over.

      In principle, Ubuntu itself creates the space allocated for Swap, but this is no longer automatic in recent Ubuntu versions, I believe; otherwise, it is 1 to 1.5 times the size of the RAM, but normally we shouldn't have to worry about this in the default "side by side" installation.

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  10. alb05 Posted messages 29 Status Member
     

    FANTASTIC, it worked.

    The installer offered me the "alongside" option and created a D: partition on its own.

    I deduce that the root cause was a bad format (GPT) of my installation USB drive.

    In MBR, it became compatible with my old BIOS and Windows on C:

    For your information, the boot time with Ubuntu is 2 minutes max, while my Windows takes at least 5 minutes when it doesn't have to download daily patches.

    A big thank you @brucine StatusMember for your patience and the help provided.

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