TeraByte Unlimited

Brian K wrote: Fri Feb 21, 2025 4:51 am Gary,

If you created a NTFS partition on a blank empty drive then that drive was still a MBR disk. The Windows install then had to create a GPT disk.
I always let BIU create a GPT disk first and then create a NTFS partition for the Windows install. Never had an issue with creating the partition in BIU.

Hey Brian. But that's exactly what I did at first. I had a blank, new 1TB Nvme drive on which I created a 500MiB partition inside BIU with Partition Work, formatted it to NTFS, booted out of BIU and directly to my Win11 USB install drive, and started the Windows 11 installation. After copying files and whatever Windows then wants to go through a series of reboots to continue on and finish the install. At that point (ie, the first reboot), my machine just went into a reboot loop. Reactivating BIU and getting back to my Boot List made no difference, I couldn't finish the install. So I changed my technique as described in my post above and it worked. I do not understand why my initial setup and installation failure in fact does not happen to you. I honestly am still confused by BIU even after all these years of using it.

Brian K wrote: Fri Feb 21, 2025 5:50 am Gary, an interesting test.

128 GB SSD. Blank. It was converted to GPT in BIU and a MSR was now seen at the beginning of the drive. The MSR was Slid to the end of the drive. A 100 GB NTFS partition was created and the MSR was slid up to the end of the NTFS partition.

Win11 was installed to the NTFS partition.
No problem. Win11 booted.

In BIU PartWork the NTFS partition had been resized smaller and there was a 642 MiB Recovery partition, then the MSR.

So Win11 works with the MSR before or after the NTFS partition.

Geez I don't understand why it works for you but not for me. I'm on an Asus Crosshair VII x470 motherboard. I have my BIOS setup with Secure Boot disabled but I still have my CSM (compatibility support module) set to enabled. I just don't get it.

Gary, I had a MSR on the drive before I started the install. From what I understand, your MSR was created during the install. Is that correct?

Brian K wrote: Sat Feb 22, 2025 1:46 am Gary, I had a MSR on the drive before I started the install. From what I understand, your MSR was created during the install. Is that correct?

Yes, correct. But forgive my ignorance here. Since when does the creation of a GPT partition automatically create a Microsoft MSR? The two are mutually exclusive, are they not? You would only find an MSR with the installation of a Microsoft OS, not the mere creation of a GPT partition, yes? Or am I just totally misunderstanding something here?

If you have a blank drive in BIU and you click Change Disk Type to GPT, a MSR will be immediately created. 16 MiB at the start of the drive. The rest of the drive will be Free Space. The drive will have a GUID partition table rather than a MBR.

https://en.wikipedia.org/wiki/GUID_Partition_Table

Wow Brian thank you TONS for that link. I totally went through it and was surprised to read about so many things I have forgotten! Geez I feel old.

Anyway, as I understand it thanks to you and this really great Wiki write-up, the MSR (Microsoft's System Reserved partition) is more formally identified in the paper as the Protective MBR (at LBA 0) with partition type EEh. Just for fun I confirmed that reading the MBR under BIU. So it appears to be integral to the GUID Partition Table (GPT).

With that information I still don't know what I was doing wrong with my first Win11 install to a dedicated drive. In this case it was a new Nvme drive installed to a PCI-E expansion card plugged into my 4x slot. Before I attempted the Windows install I tested the new Nvme card by installing Linux Mint to it. The installation went easy and the distro functioned as expected. Later, I deleted the entire partition and then prepared the drive for the Windows 11 installation. That's where I ran into problems as described in this thread, but they appear to be because of my lack of knowledge with both the proper use of BIU and partition preparation.

One other thing, why are there no protective MBR's (MSR's) created when I install Linux systems?

Edit to the question: If the MSR is just a Microsoft thing and created by a Windows installation, I don't understand why this reserve partition would be created just by the creation of a GPT disk.

Last thing, I found this paper vis-a-vis the footnotes in the Wiki link you provided. Only a nerdy will find it interesting (I did!), and was written by an IBM dev back in 2012. It's called Make the most of large drives with GPT and Linux. Link: https://developer.ibm.com/tutorials/l-gpt/

Gary, thanks for your link.

There is more confusion. The System Reserved partition (SRP) is not the MSR. The SRP is the active partition on a MBR disk. The MSR is the Microsoft Reserved Partition. The Protective MBR is not the SRP or the MSR.

The MSR is discussed here...

https://learn.microsoft.com/en-us/previ ... dfrom=MSDN

This page is a little dated. Microsoft has made changes to the MSR size.

Brian K wrote: Sat Feb 22, 2025 7:27 pm Gary, thanks for your link.

There is more confusion. The System Reserved partition (SRP) is not the MSR. The SRP is the active partition on a MBR disk. The MSR is the Microsoft Reserved Partition. The Protective MBR is not the SRP or the MSR.

OMG

The MSR is discussed here...

https://learn.microsoft.com/en-us/previ ... dfrom=MSDN

This page is a little dated. Microsoft has made changes to the MSR size.

Thank you for that. Thus:

What is a Protective MBR?

The Protective MBR, beginning in sector 0, precedes the GPT partition table on the disk. The MBR contains one type 0xEE partition that spans the disk.

What is a Microsoft Reserved Partition (MSR)?

The Microsoft Reserved Partition (MSR) reserves space on each disk drive for subsequent use by operating system software. GPT disks do not allow hidden sectors. Software components that formerly used hidden sectors now allocate portions of the MSR for component-specific partitions. For example, converting a basic disk to a dynamic disk causes the MSR on that disk to be reduced in size and a newly created partition holds the dynamic disk database.

What partitions are required by Windows?

For UEFI systems, the boot drive must contain an ESP, an MSR, and at least one basic data partition that contains the operating system. Only one ESP should exist on a system even if multiple operating systems are installed on that system. In a mirrored boot configuration there may actually be two drives with an ESP but they are considered to be a redundant copy of the same ESP. Each data drive must contain at least an MSR and one basic data partition.

Thanks for all your help with this journey I'm on...I think.

To summarize a second Win11 install to a computer with BIU already installed. You can install a new Win11 to the current drive or add another drive.

If installing to a new blank drive. In BIU create a GPT disk, then create a NTFS partition for the future Win11 after the 16 MiB MSR.

Or, leave the drive blank and create the NTFS partition during the Win11 install. The Microsoft installer will create a GPT disk with a MSR.

Brian, thank you again for the helpful information and for my reeducation. You effort is highly appreciated.