Help with the Mysteries of extra Windows 10 partitions?

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Help with the Mysteries of extra Windows 10 partitions?

Postby tbessie » Mon Jan 21, 2019 12:20 am

Hi all...

On the other Windows 10 machines I've got, Windows seems to install 2 or 3 extra partitions on a fresh install (not an upgrade). I didn't try to install BootIt UEFI on those machines. Just looking at one of them, I see:

1. 499MB "OEM Partition"
2. 100MB "EFI System"
3. 820MB "OEM Partition" (this one is in the middle of my other partitions on the boot drive)

I know the EFI System partition is for booting; I suppose one of the other OEM Partitions is a recovery partition. Not sure what the other OEM partition is for (all of them are hidden/unmounted).

I just recently installed first BootIt UEFI and then Windows 10 on a machine of mine (also fresh installs). I let BootIt UEFI install itself where it wanted (400MB at start of drive). Then I installed Windows 10 on the remaining space. At first it said it had created 3 partitions - 2 smaller ones and 1 big one. Later, when I checked, the extra partitions seemed to have disappeared (or at least weren't shown in the Windows Drive Manager). Later, looking at the drive with the BootIt partition manager, I saw that at least one of the extra partitions was still there, but hidden from the Drive Manager.

When I first booted the system, it looks like Windows had overridden my setup to boot to BootIt. I'm not sure where it would have put its boot files, though; perhaps in BootIt's EFI partition?

In any case, I ran BootIt from a USB drive, and it appeared to have automatically corrected things, so when I removed the USB stick, it booted to BootIt again. I MAY have changed the boot partition in the BIOS (there was a lot going on in this install, so I can't recall now).

I'm not quite used to UEFI booting, especially when I try to use a non-Windows boot manager. One thing that boggles my mind - what happened to the other partitions Windows created when I installed it? They seem to have just... disappeared?

Can someone chime in and tell me what's going on here? I'm used to boot changes happening only manually, when I direct software to make them happen. All these magically new and/or disappeared partitions, etc. are confusing me.

- Tim
tbessie
 
Posts: 6
Joined: Thu Nov 28, 2013 2:20 pm

Re: Help with the Mysteries of extra Windows 10 partitions?

Postby TeraByte Support » Mon Jan 21, 2019 10:27 pm

you'd start by looking in partition work. II f there, then you look at the
boot config for any hiding. If all good, then you go to drive management in
windows and assign drive letters to the partitions if you want them to have
them.

"tbessie" wrote in message news:16275@public.bootitbm...

Hi all...

On the other Windows 10 machines I've got, Windows seems to install 2 or 3
extra partitions on a fresh install (not an upgrade). I didn't try to
install BootIt UEFI on those machines. Just looking at one of them, I see:

1. 499MB "OEM Partition"
2. 100MB "EFI System"
3. 820MB "OEM Partition" (this one is in the middle of my other partitions
on the boot drive)

I know the EFI System partition is for booting; I suppose one of the other
OEM Partitions is a recovery partition. Not sure what the other OEM
partition is for (all of them are hidden/unmounted).

I just recently installed first BootIt UEFI and then Windows 10 on a machine
of mine (also fresh installs). I let BootIt UEFI install itself where it
wanted (400MB at start of drive). Then I installed Windows 10 on the
remaining space. At first it said it had created 3 partitions - 2 smaller
ones and 1 big one. Later, when I checked, the extra partitions seemed to
have disappeared (or at least weren't shown in the Windows Drive Manager).
Later, looking at the drive with the BootIt partition manager, I saw that at
least one of the extra partitions was still there, but hidden from the Drive
Manager.

When I first booted the system, it looks like Windows had overridden my
setup to boot to BootIt. I'm not sure where it would have put its boot
files, though; perhaps in BootIt's EFI partition?

In any case, I ran BootIt from a USB drive, and it appeared to have
automatically corrected things, so when I removed the USB stick, it booted
to BootIt again. I MAY have changed the boot partition in the BIOS (there
was a lot going on in this install, so I can't recall now).

I'm not quite used to UEFI booting, especially when I try to use a
non-Windows boot manager. One thing that boggles my mind - what happened to
the other partitions Windows created when I installed it? They seem to have
just... disappeared?

Can someone chime in and tell me what's going on here? I'm used to boot
changes happening only manually, when I direct software to make them happen.
All these magically new and/or disappeared partitions, etc. are confusing
me.

- Tim

TeraByte Support
 
Posts: 2701
Joined: Thu May 05, 2011 3:37 pm

Re: Help with the Mysteries of extra Windows 10 partitions?

Postby tbessie » Fri Jan 25, 2019 2:03 am

I appreciate your reply, but what I was asking was more a general question of how Windows interacts with other apps that work with partitions in an UEFI environment. Why would partitions that were created, later disappear? Why would BootIt UEFI be able to modify the on-disc UEFI boot information after Windows overwrites it, when I boot from a BootIt UEFI USB drive? Where does Windows put its boot info if I've already created a UEFI partition that has BootIf UEFI on it? etc.

- Tim
tbessie
 
Posts: 6
Joined: Thu Nov 28, 2013 2:20 pm


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