Windows 11 [2021]
- Thread starter eastmen
- Start date
hoom
Veteran
Command line stuff to mount it & then browse around
support.microsoft.com
I saw some stuff indicating you can mount it in a way that shows in File Explorer but it didn't want to work for me.
“We couldn’t update system reserved partition” error installing Windows 10 - Microsoft Support
When upgrading to Windows 10, you may encounter the error “We couldn’t update system reserved partition”, error code 0xc1900104, or error code 0x8000f0922.
support.microsoft.com
Yeah, the only way to get there is to use the arcane CLI magica. This is because these reserved partitions use a unique partition type identifier which the Windows disk management toolchain understands should not be exposed to users.
As for Microsoft "fixing" the issue, it can be non-trivial. Essentially you need to grow the partition, which means whatever partition is logically next needs to shrink to make room. What if it doesn't have room to shrink? What if it's not the only remaining partition on the disk? The actual answer is to get rid of the manufacturer crap relocated to another partition, which honestly is easier than it might sound. Here's what would happen: the very last partition on the disk would be evaluated and, if ~100MiB is available, the partition is shrunk and a new partition created. The new partition would then be formatted FAT32 (so it's invalid for bitlocker) and then loaded with a WinRE image with the relevant manufacturer diags / recover tools. Finally, the BCD file in the EFI partition would then be updated to change the recovery image pointer to the new partition.
I've actually done this sort of work at $Job[-2]. We wrote our own recovery methods based on Windows PE, scrunched the main partition down just a smidge, and then dropped all our hotness into a new partition. The silly part of my story is, we used an NT6.1 (Vista / Win7) WinPE image and related bootloader to build a recovery method and boot process for a WinXP-based image. This was also nearly 15 years ago
As for Microsoft "fixing" the issue, it can be non-trivial. Essentially you need to grow the partition, which means whatever partition is logically next needs to shrink to make room. What if it doesn't have room to shrink? What if it's not the only remaining partition on the disk? The actual answer is to get rid of the manufacturer crap relocated to another partition, which honestly is easier than it might sound. Here's what would happen: the very last partition on the disk would be evaluated and, if ~100MiB is available, the partition is shrunk and a new partition created. The new partition would then be formatted FAT32 (so it's invalid for bitlocker) and then loaded with a WinRE image with the relevant manufacturer diags / recover tools. Finally, the BCD file in the EFI partition would then be updated to change the recovery image pointer to the new partition.
I've actually done this sort of work at $Job[-2]. We wrote our own recovery methods based on Windows PE, scrunched the main partition down just a smidge, and then dropped all our hotness into a new partition. The silly part of my story is, we used an NT6.1 (Vista / Win7) WinPE image and related bootloader to build a recovery method and boot process for a WinXP-based image. This was also nearly 15 years ago
I assume you won't have a problem because you installed Windows yourself so there's nothing in the EFI partition that shouldn't be there.Heres my C: drive
View attachment 10281
The win 10 install progam created those partitions I did bugger all
If you fail to create partitions when installing Windows and just click on your drive and click next, what happens? In the past I've done this and it never caused any immediate problems. But I probably haven't done that since the days of MBR.
@Davros yes, the default installer will create those partitions -- notice the sizing it elects? The larger first partition contains a smaller WinRE bootable image which permits the special "safe mode" function of Win10 and later. The tiny 2nd partition is the EFI chain loader section where a bitlocked volume is verified against the local TPM hardware and then chain-loaded -- that is, if you elected to bitlock your C: drive.
@homerdog You can force the RTM version of Win10 to load into a single partition, however you can never bitlock that volume. I'm not sure if the latest releases of Win10 or Win11 installation media allows this behavior...
@homerdog You can force the RTM version of Win10 to load into a single partition, however you can never bitlock that volume. I'm not sure if the latest releases of Win10 or Win11 installation media allows this behavior...
Used to it didn't. If you just clicked next it wouldn't partition the drive. You could install Windows that way but I guess you'd have problems down the line like can't use bitlocker.
Silent_Buddha
Legend
On machines with existing Windows installations that were installed prior to EFI becoming the norm (thus no EFI partition), Windows would default to putting the EFI partition on a different drive if available. If another drive wasn't available, it would resize the partition on the sole drive and append an EFI partition to the end of the drive. If there wasn't enough free space to do this Windows would give a message that it was unable to install Windows due to insufficient free space (or some similar wording).
I think Windows 11 will probably restructure your C: drive assuming there's enough free space, however, if the EFI partition is in a different location (different drive, or end of a drive) due to Windows 10 installing it there, then a Windows 11 installation will default to using that location for the EFI partition (IE - it'll continue to use it).
Regards,
SB
Stupid anecdote time
My motherboard provides two NVMe sockets, however only one of them is PCIe v4, the other is PCIe v3. I wanted the higher throughput interface for my bigger games and bulk media (eg VM disk files) so I installed my 2TB Sammy 980Pro in the v4 slot, and my 1Tb Sammy 980Pro in the v3 slot for running Windows OS and whatever else didn't seem to need the disk throughput as much. As it turns out, the v4 slot was the "first" ACPI bootable storage position and it couldn't be changed.
Thus, the tiny EFI partition is on my first ACPI disk which is the 2TB PCIe v4 interface, and then the Windows installation is on the second ACPI disk whic is the 1TB PCIe v3 interface. Once Windows is fully booted, the 1TB "second drive" is actually drive letter C:, and my 2TB "first drive" becomes letter D: because that's how I have it logically configured. So there ya go, a use case for why my EFI partition and my Windows system partition are on physically separate disks.
Silent_Buddha
Legend
It is, especially if you don't know it and upgrade (replace) the drive that the EFI partition was on, thus making Windows unbootable.
Thankfully, using the recovery tools you can rebuild an EFI partition to make Windows bootable once again.Regards,
SB
You could have prevented that by installing windows when there was only the v3 drive in the system
I get random activity on my E: drive - I assume it's because it's listed as disk 0 (my C: drive is disk 3 the sata drives get listed before the nvme drives) that shouldnt be happening because it just contains games and nothing on it is running
No need, just tell the installer where you want the system partition to live and it "just works." The system utilities which understand ACPI order (eg the disk management GUI mode and CLI mode, as well as the Samsung update manager software thing) still show the 2TB drive in the first position, and no manner of timed or ordered hardware installation would change it. This is because the PCIe slot ID of the v4 NVMe socket is lower than that of the v3 NVMe socket.
hoom
Veteran
This is all very reminiscent of problems where MBR would get put on the wrong drive if you didn't only have the one you wanted it to be on when doing a fresh install.
I had a looong time with my MBR running on an old slow spinny disk.
I couldn't seem to clear out even after I'd moved to a SATA SSD system drive & done a clean install with only the SSD installed, that bugger kicked back in as soon as I plugged the offending spinny disk back in.
I think only actually fixed when I migrated to my first M2 drive.
I had a looong time with my MBR running on an old slow spinny disk.
I couldn't seem to clear out even after I'd moved to a SATA SSD system drive & done a clean install with only the SSD installed, that bugger kicked back in as soon as I plugged the offending spinny disk back in.
I think only actually fixed when I migrated to my first M2 drive.
EFI is more flexible in this regard because you can always create a new EFI partition and the UEFI BIOS should have no problem using it to boot.
It's just that Windows does not have a nice GUI tool to do that, generally you'll have to use diskpart and it's is quite dangerous.
It's just that Windows does not have a nice GUI tool to do that, generally you'll have to use diskpart and it's is quite dangerous.
Given what I'm capable of in this space, and have been for the past 30 years, I have zero concerns.
I find diskpart very stressful to use. Select the wrong disk or volume (very easy to do) and you can ruin your life with just a few key presses.
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