Windows 10: Installing some OS's in UEFI and some using Legacy BIOS

Hello,

I've installed Windows 10 and Ubuntu using UEFI.
But, now I created a bootable USB for a Linux that does not support UEFI, but only Legacy.
I mean, when I plug the USB to my laptop, the UEFI does not recognize it, only the Legacy BIOS does.
Is it possible to simply proceed to install the other Linux using Legacy mode? Or it will cause problems?

Thanks

:)

 

UEFI: USB OR JUST USB?

Hi,

The difference is that you need the UEFI SanDisk to boot and install into a UEFI Bios enabled machine...

You would select the regular SanDisk for Legacy Bios...

For instance... now you are installing Windows and would most likely be using UEFI Bios if this is a newer machine... You would select the UEFI SanDisk...

If for instance you were trying to boot a USB flash drive with some type of bootable utility, you may want to select the regular SanDisk...

BTW... Your HDD will be Initialized differently when installing as UEFI or Legacy, but both format as NTFS...

UEFI installations require the HDD to be initialized as a GPT drive, and Legacy installations require a MBR drive...

 

Windows 10 won't boot

There isn't total uniformity in UEFI or Legacy BIOS. Each computer is different, but there is
some continuity of terms.

I think secure boot is in UEFI only, if at all. Maybe you don't have secure boot within your UEFI. I really don't know.

I thought that CSM = Legacy BIOS but yours seems to be GSM so... you see what I mean?

I seem to recall that one must switch to UEFI mode in the BIOS, in order to boot from installation media on newer computer devices.

All of this is somewhat vague and a blur to me because I'm old fashioned Legacy BIOS myself, and do not deal with switching back and forth between UEFI and CSM Legacy BIOS.

How is the installation going?

 

I am never a fan of using dual boot. I have Windows 10 installed on a separate GPT SSD and Linux installed in MBR SSD and run them separately using Boot Menu so they are completely independent from each other.

I did mention in your other thread that dual booting using MBR is preferable which you can set the Windows boot manager and GRUB boot loader separately. The traditional way is Linux override the MBR and took over the booting process for both Windows & Linux. The non traditional way is to put the GRUB Boot loader in its own partition then use Easy BCD to set up the dual boot, this way they are independent so if there's an update/upgrade from either one, you won't break anything. In addition, you'll get a nice GUI dual boot Menu from Windows, not the ugly GRUB.

Here's an example:

• GRUB controls the booting process for both Windows and Linux
• Put GRUB in its own partition and use Easy BCD to set up dual boot.
  NOTE: During Linux installation, you have to tell Linux not to use sda (MBR in Windows) but its own partition.

 

Sorry I may have not understood you correctly. I am not too expert in these things.
The problem now is that I already have Ubuntu and Windows installed on UEFI, but the 3rd OS (another linux) is not shown on UEFI in the bios.

What exactly is the connection between MBR and UEFI?
*I will try to do stuff with Easy BCD now.
**How do I put grub in a separate partition if I haven't done that ? should i reinstall Ubuntu and
Windows 10?

***Earlier I accidentally installed a software called EasyUEFI instead of Easy BCD, is it a bad software?

****Should I completely change the bios to ALWAYS run as Legacy instead of UEFI and reinstall all using Legacy?
(I can't find the connectiom between UEFI/Legacy to MBR/Grub and the bootable OSs . )
Thank you!

*Edit: I installed Windows and Ubuntu when my bios was set on UEFI. so in order to make it work, I must remove all, and install them when LEgacy BIos is on and enabled first, right? there is not escape than making a clean install of Windows and Ubuntu from the Legacy menu in the bios instead of uefi?

 

EasyBCD will not work. If you run EasyBCD with the PC currently booting in EFI. You will get this Warning Message.




As you found out. Setting dual boot with Windows & Linux running in EFI mode, you'd need another boot manager such as rEFInd. With MBR is easy as mentioned above.

I don't own a Laptop so I am not sure how the EFI firmware works with CSM enabled/disabled but with my desktop, it does support both EFI+MBR, meaning both will be listed in the boot menu whether My OS was installed using EFI or MBR.

I don't think it is possible to dual boot with a mix between EFI and MBR even under Windows Environment. You either have both EFI or both MBR.

 

Thanks.
I don't think my laptop supports both at the same time. I think you can choose either MBR or EFI.
truly I got this message that you posted above in the image.
So what I need to do now is to wipe my hard drive, and clean install everything on the MBR? (Which means no secure boot or fastboot, right?)

*edit: My UEFI does not have secure boot option. why do I have UEFI then? Is it sort of synonym for GPT then?

**Question: when I say "Legacy mode" it's the same as saying "MBR" right?

 

Simply put: when installing Windows:
UFI Firmware uses GPT (GUID Partition Table) Partition scheme
Legacy BIOS uses MBR (Master Boot Record) partition scheme

 

Thank you!
Since I do not have the knowledge of the in-depth software meaning of GUID Partition Table and Master Boot Record, I would like to know then, (if you can put it simple again): If I created Ubuntu and Windows in a GUID, and the 3rd Linux in MBR, is it possible that during installation of the third Linux, it recognized that I have the other 2 in UEFI and moved itself to the GUID and did not position itself in the MBR after it detected that?

 

Do not try to mix MBR and GPT/UEFI. It is asking for trouble. Just recreate your Linux usb stick with GPT/UEFI support, assuming that the linux distribution supports UEFI. All current *buntu flavors do.
For Ubuntu 15.10 Unetbootin no longer works. Maybe rufus still does, I do not know. dd does work:
Code: # dd if=<your iso file> of=/dev/sdb bs=1024[/quote] assuming that /dev/sdb is your usb stick. I do not think the bs parameter matters very much.

If the dd command scares you, you can have a look at https://help.ubuntu.com/community/Installation/FromUSBStick#mkusb_-_dd_image_of_iso_file_to_USB_device_safely

 

Agreed and much easier using MBR as mentioned above.

assuming that /dev/sdb is your usb stick. I do not think the bs parameter matters very much.

If the dd command scares you, you can have a look at https://help.ubuntu.com/community/Installation/FromUSBStick#mkusb_-_dd_image_of_iso_file_to_USB_device_safely
[/quote] Need not use Rufus nor dd. Just format the stick with FAT32, use Winzip/Winrar/7-zip to extract the content of the ISO to the root folder of the stick, open Disk Management to set "Active" then you can boot from it.

 

I don't know if it means that I mixed MBR with UEFI, maybe you can understand:
I had in my BIOS the UEFI Enabled, and Legacy disabled, with 2 OS installed: Ubuntu and Windows 10.
The 3rd Linux, was not detected in the UEFI boot menu, so I enabled Legacy, and it was detected, so I chose it from this menu that appears in the BIOS under Legacy boot options.
Then the installation started. when it started, it did prompt me that I have Ubuntu installed, and what I'd like to do? I chose to install the boot loader inside /dev/sda2 (which later realized was Windows UEFI partition, and not the grub partition of Ubuntu), and from some reason, it did not cause any problems, and I now see all 3 OS's from the GRUB menu, and no problems.

So I think that the other Linux does support UEFI, but my laptop's BIOS did not detected it on the menu of the UEFI boot options from some reason, and after I installed it when Legacy bios was enabled, it moved itself to the UEFI part. (I'm talking general terms, because as I said I do not really know what's going deeper like you guys, but maybe you can understand from my description)

Thank you for the help