XPS 8930, BIOS boot sequence problems

I did not think you can manage multiple boot configurations in the BIOS. I think you need to be able to edit the Boot Configuration Data (BCD) that the Windows Boot Manager uses to boot the system. Without doing that, F12 is the only option. The BIOS Setup (F2) does not show the boot order although it does display the names and drives installed. The BIOS shows the Boot Options (Windows Boot Manager and Onboard NIC devices.

I don't what to say about the boot sequence/order changing other than perhaps one of the bootable drives is not detected at bootup.

The boot order in the Bios should stay you have it set.  If a drive disappears for some reason during a boot the Bios priority may be changed.

Each Windows Boot Manager entry should have some type of ID.  The F12 listing is just that, a list of bootable devices.  If you use the F12 key to boot, that selection does not change the Bios boot order.

If you have identical drives or a cloned install, it can be problematic.

How you install the various boot systems can also make a difference.  UEFI systems put all the boots file in the one EFI system partition.  If you install with a single drive, it will create that partition on that drive, so you can install independent or parallel installs by having only the one drive for each install.

If you use the admin command prompt and type bcdedit, it will show your boot manager and OS loaders.  You can copy and paste that listing if you want.

If you were to get a Windows Build upgrade while having used the F12 boot options, I do not know for sure how the system would handle the upgrade if that specific install was not first priority in the Bios during subsequent reboots.  

Actually the BIOS does show the boot order. It allows rearrangement of the order and disabling of drives.  The problem -is not- that the drives do not show, they sometimes get -rearranged- or their names are changed from the DRIVE to Boot Manager, which makes it CONFUSING when you have '3 Boot Manager' entries and don't know what drives they are. 

BCDEDIT is not an option unless Microsoft Boot Manager only is being used.  Boot Manager is just -one option- in the BIOS or F12, a specific DRIVE can also be selected as the bootable SDD's and HD's are also listed. At one time the BIOS and the F12 showed the same boot sequence but now they don't even show the same drives.

The BIOS is current as well as the OP SYS. 

I can't imagine no one has had this problem unless they only have ONE bootable drive.  If so, they will be up a creek if their only bootable drive fails.

If the Bios is using a drive designation then that is normally a non-UEFI boot.  The UEFI versions will say Windows boot manager and may have info after that part to designate a specific drive is you have more than one.

I many cases, the single EFI system partition handles the boots and contains OS loaders for the other installs.

I have never tried because it might mess up your boot but the Boot manager is a Description and possibly changed if you have several drives with a EFI System partition.

"The boot order in the Bios should stay you have it set.  If a drive disappears for some reason during a boot the Bios priority may be changed."

Therein lies the problem I am having, it DOES change without my input.

I have multiple drives each with separate EFI partitions.  Bcdedit only shows the boot information on the specific drive that is currently booted not others.  I can boot one or another or another and perhaps do something like update the OP SYS. Then I may boot again and the BIOS ORDER has changed so I have to F12 and/or go into setup and 'rearrange' the boot order. 

Sometimes the BIOS even changes the NAME, EG: I specify a name which reflects the drive, like Samsung 480, it may be changed to Boot Manager at some point.  When this happens and I wind up with 2 or 3 "Boot Manager" entries in BIOS . . . .which one is which?  THAT is what I don't like and is annoying.