Dual BIOS, hdd hivernating at boot and UEFI - explanations, help?

[mzjo]

I have just acquired a computer (free in a flat clean-up job, it was left by a deceased owner for the tip). It can only be a supermarket job but new enough to have (the detested) W10.
Since my objective would be to put some flavour of Linux on it I tried to change the boot sequence. The W10 option appears to be something called UEFI. The boot sequences seem odd to me in that each option appears to be giving a list of three boot sources. Eventually I got it to boot off CD/DVD to test out what happened with a CD. On boot up a message appeared, saying thatthe hard drives were hivernated. Boot up with CD worked fine.
Normally when I have a boot sequence giving CD first booting without the CD will default to the next boot source available, in this case UEFI. However this box just gives me a message that the boot media is absent! No boot unless I go back and change the BIOS settings again (or have I irreparably destroyed the W10 boot?). If I install to a hdd partition will the partition still be "hivernated" at boot?

The motherboard is a Gigabyte GA-B75M-D3H. It apparently has a dual BIOS and on the board there are in fact 2 locations marked M Bios and B Bios. Can anyone explain to me what that is all about? I think there are two key options for getting into the BIOS, AFAICR I used Esc.

Any explanations accepted. This sort of modern stuff is confusing me, although I manage Ok with the old single core 32bit stuff.

[philip]

I assume you mean "hibernated". I think that means Windows went into hibernation while running rather than doing a full shutdown. Hibernation is designed to make the machine come back up faster, and in the exact same state as before hibernation. To achieve this Windows marks the filesystem as "hibernated" and that mark is detected when Windows boots so it knows what to do.

Linux will generally fail to mount a Windows filesystem that is marked hibernated. If you reformat the drive under Linux the hibernated setting will no longer exist.

Old computers used BIOS to get the OS running, and used a disk layout known as MBR. UEFI is a more modern BIOS and uses a disk layout known as GPT. Most UEFI systems also have support for the MBR layout. Linux supports both MBR and GPT and generally you get to choose when you partition a disk. Typically you need to configure your UEFI/BIOS to boot either from MBR or GPT and this "bios" setting needs to match the partitioning you chose in Linux.

[mzjo]

Thanks for that. I will have to look a bit further into this. Yes hivernation must be hibernation, this box is speaking french even at boot!

The windows partitions don't mount, aren't even accessible , at boot (I used Puppy, that looks for save files in the hard drives and it couldn't) but they were accessible once the system was running.

Having little experience of changing discs on this sort of system, what do I need to do when I swap the old disc for a new one (the whole hard drive, not repartitioning)? Will it just be found once it has been formatted (like the last ones i have replaced)? I would prefer to start with a clean disc!

Does the dual boot mention simply mean that it supports MBR and UEFI?

[philip]

I guess "dual boot" is a Gigabyte term.  The motherboard manual appears to be available:
https://www.gigabyte.com/Motherboard/GA-B75M-D3H-rev-10#support-manual

If you repartition and format the old disk from the Linux installer it will effectively be clean.