Thank you. I was thinking that Windows allows you to change to Uefi (somehow) and once done I would simply install my new Ubuntu Studio as Uefi. What about deleting the ext4 partition to remove Ubuntu? Is this a good idea?
Standard procedure is Windows tools for Windows & Linux tools for Linux. Or use gparted on live installer to remove ext4 partition, if you have nothing to backup or have good backups. Windows may not show partition correctly.
Windows has a tool to convert BIOS/MBR to UEFI/gpt, but we have seen many post that they just had to reinstall. Or make sure you have good backups. And you cannot restore MBR partitions to gpt drives, but can easily restore data in a MBR partition to a gpt partition. Windows requires MBR(msdos) for BIOS boot and requires gpt partitioning for UEFI boot. Windows has required vendors to install in UEFI/gpt since 2012 and release of Windows 8. BIOS mode was only for large customer with older BIOS only systems to be able to use newer version. Laptop systems since about 2020 may say BIOS, but once in āBIOSā will say UEFI only.
My system is an old dell inspiron originally windows 7 but updated to 10. It seems if I go to the screen on boot where I turned off secure boot I can choose to change to UEFI. I have a usb drive I can boot to with Ubuntu studio and then use that to remove the ext4. I donāt yet have anything in Ubunto to backup and Windows 10 files are already backed up so Iām not worried about reinstalling windows if necessary.
My BIOS version is from 2013-12-03 so gives you an idea of the age of the desktop inspiron I have
If Dell has a newer version of UEFI/BIOS, best to update to it.
You have to also convert drive from MBR(msdos) to gpt as Windows requires gpt for UEFI boot. That at minimum will require Windows updates or reinstall of its boot loader as instead of using MBR, it puts boot files into the ESP - efi system partition.
To boot in old BIOS mode, UEFI Secure Boot must be off.
If you are planning to re-install Windows 10 in UEFI mode with GPT, just allow the installer to use the whole disk and the ext4 partition will be overwritten.
By the way, Windows 10 loses support in October 2025.
All this was to be ready for updating to Windows 11 but I just found out this system will not work with Windows 11 (cpu not supported and a possible additional motherboard problem) so Iāll keep windows 10 till October then use just Ubuntu.
My system has Dual boot running and both windows 10 and Ubuntu running but I did not change to Uefi as I could not convert Drive using microsoftās tool, but, as Iām not loading windows 11, that no longer matters. I may try again when I get rid of Windows 10.
Thanks for all the help!
There is the option of running Ubuntu in an external powered USB container / docking bay / SSD, provided that you have USB 3.0 port in your host Inspiron. I have Dell tower Inspiron and I have Windows 10 in the Dell host, and two separate caddies in StarTech dual docking bay containing UEFI Ubuntu (EFI boot partition) and a shared datavault in second caddy. I use rEFInd for dual booting.