Need help upgrading to Windows 11 (boot disk is MBR)


NapMan

New member
Local time
10:11 AM
Posts
12
OS
Windows 10
I discovered I will be unable to upgrade to Windows 11 because my boot disk is partitioned as MBR. PC Health Check says I need to enable Secure Boot, but it is enabled in the BIOS.
I did some searching and found ways to convert the disk to GPT without losing any data but it did not work. I tried a partitioning app (AOMEI) and it states that I cannot convert it because my boot partition and system partition are on different disks. I don't know why it ended up like this. I'm looking for help on how I can correct this without having to start from scratch. Here is what my disk info looks like:

IMG_0285.JPG

It looks like the system partition is small enough to fit onto the SSD (Disk 1) but I don't know how to move it. I'm looking for any advice and/or help in this matter.
I didn't build the system, my partner did.

I appreciate any help.
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB
I discovered I will be unable to upgrade to Windows 11 because my boot disk is partitioned as MBR.
Welcome to Eleven Forum NapMan

That's not your only barrier to being offered the W11 upgrade. Your AMD Ryzen 5 1600 is not on Microsoft's list of supported AMD processors.

There are ways to install W11 or upgrade to W11 on unsupported devices. You'll find plenty of workarounds in Eleven Forum posts, and even Microsoft have published some ways to do it. But your existing Windows 10 will be fully supported with cumulative and feature updates until October 2025.

I would not recommend it if this is the machine that you rely on for daily use. I would only do it on a spare PC for test purposes, such as on my completely unsupported Legacy MBR, 1st gen i5, TPM 1.2 System Two below.

Microsoft said:
Warning:
  • Microsoft recommends against installing Windows 11 on a device that does not meet the Windows 11 minimum system requirements. If you choose to install Windows 11 on a device that does not meet these requirements, and you acknowledge and understand the risks, you can create the following registry key values and bypass the check for TPM 2.0 (at least TPM 1.2 is required) and the CPU family and model....
 
Last edited:

My Computers

System One System Two

  • OS
    Windows 11 Home
    Computer type
    Laptop
    Manufacturer/Model
    Acer Aspire 3 A315-23
    CPU
    AMD Athlon Silver 3050U
    Memory
    8GB
    Graphics Card(s)
    Radeon Graphics
    Monitor(s) Displays
    laptop screen
    Screen Resolution
    1366x768 native resolution, up to 2560x1440 with Radeon Virtual Super Resolution
    Hard Drives
    1TB Samsung EVO 870 SSD
    Internet Speed
    50 Mbps
    Browser
    Edge, Firefox
    Antivirus
    Defender
    Other Info
    fully 'Windows 11 ready' laptop. Windows 10 C: partition migrated from my old unsupported 'main machine' then upgraded to 11. A test migration ran Insider builds for 2 months. When 11 was released on 5th October it was re-imaged back to 10 and was offered the upgrade in Windows Update on 20th October. Windows Update offered the 22H2 Feature Update on 20th September 2022. It got the 23H2 Feature Update on 4th November 2023 through Windows Update.

    My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB ssd, supported device running Windows 11 Pro (and all my Hyper-V VMs).

    My SYSTEM FOUR is a 2-in-1 convertible Lenovo Yoga 11e 20DA, Celeron N2930, 4GB RAM, 256GB ssd. Unsupported device: currently running Win10 Pro, plus Win11 Pro RTM and Insider Beta as native boot vhdx.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 4GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro, plus the Insider Beta, Dev, and Canary builds as a native boot .vhdx.
  • Operating System
    Windows 11 Pro
    Computer type
    Laptop
    Manufacturer/Model
    Dell Lattitude E4310
    CPU
    Intel® Core™ i5-520M
    Motherboard
    0T6M8G
    Memory
    8GB
    Graphics card(s)
    (integrated graphics) Intel HD Graphics
    Screen Resolution
    1366x768
    Hard Drives
    500GB Crucial MX500 SSD
    Browser
    Firefox, Edge
    Antivirus
    Defender
    Other Info
    unsupported machine: Legacy bios, MBR, TPM 1.2, upgraded from W10 to W11 using W10/W11 hybrid install media workaround. In-place upgrade to 22H2 using ISO and a workaround. Feature Update to 23H2 by manually installing the Enablement Package.

    My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB ssd, supported device running Windows 11 Pro (and all my Hyper-V VMs).

    My SYSTEM FOUR is a 2-in-1 convertible Lenovo Yoga 11e 20DA, Celeron N2930, 4GB RAM, 256GB ssd. Unsupported device: currently running Win10 Pro, plus Win11 Pro RTM and Insider Beta as native boot vhdx.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 4GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro, plus the Insider Beta, Dev, and Canary builds as a native boot .vhdx.
Welcome to Eleven Forum NapMan

That's not your only barrier to being offered the W11 upgrade. Your AMD Ryzen 5 1600 is not on Microsoft's list of supported AMD processors.

There are ways to install W11 or upgrade to W11 on unsupported devices. You'll find plenty of workarounds in Eleven Forum posts, and even Microsoft have published some ways to do it. But your existing Windows 10 will be fully supported with cumulative and feature updates until October 2025.

I would not recommend it if this is the machine that you rely on for daily use. I would only do it on a spare PC for test purposes, such as on my completely unsupported Legacy MBR, 1st gen i5, TPM 1.2 System Two below.



Thank you for the response. I'm confused because PC Health Check says something different:

IMG_0287.PNG
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB

My Computer

System One

  • OS
    Windows 11 Home(Beta) - 23H2 - 22635.3350
    Computer type
    PC/Desktop
    Manufacturer/Model
    Banana Junior 5600- G Series
    CPU
    AMD Ryzen 5 5600G
    Motherboard
    Asus ROG Strix B550-F
    Memory
    G.SKILL Ripjaws V Series 64GB 4x16
    Graphics Card(s)
    NVIDIA GeForce GTX TITAN X
    Monitor(s) Displays
    Viotek 32", 28" ASUS VP28U
    Screen Resolution
    1080p
    Hard Drives
    Primary SAMSUNG 970 EVO Plus
    PSU
    EVGA BQ 700w 80+ Bronze
    Case
    Zalman i3 NEO
    Cooling
    ARCTIC Freezer 7 X
    Keyboard
    Corsair
    Mouse
    Amazon Generic with Cord
    Internet Speed
    Download: 295.11 mbps Upload: 65.35 mbps T-Mobile Internet
    Browser
    Firefox and Edge
    Antivirus
    MS - Defender
    Other Info
    Speakers: Klipsch ProMedia 2.1

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB
I'm confused because PC Health Check says something different:
That's odd, your processor isn't on the MS list here:
maybe MS have now added it to the supported processors, but not got round to updating their documentation yet.

Well, if your motherboard has a UEFI bios and a lack of Secure Boot with a GPT disk is your only impediment, then it is possible to convert a Legacy/MBR install to UEFI/GPT without data loss. Be sure to make a system image with something like Macrium Reflect Free before you try though.

 

My Computers

System One System Two

  • OS
    Windows 11 Home
    Computer type
    Laptop
    Manufacturer/Model
    Acer Aspire 3 A315-23
    CPU
    AMD Athlon Silver 3050U
    Memory
    8GB
    Graphics Card(s)
    Radeon Graphics
    Monitor(s) Displays
    laptop screen
    Screen Resolution
    1366x768 native resolution, up to 2560x1440 with Radeon Virtual Super Resolution
    Hard Drives
    1TB Samsung EVO 870 SSD
    Internet Speed
    50 Mbps
    Browser
    Edge, Firefox
    Antivirus
    Defender
    Other Info
    fully 'Windows 11 ready' laptop. Windows 10 C: partition migrated from my old unsupported 'main machine' then upgraded to 11. A test migration ran Insider builds for 2 months. When 11 was released on 5th October it was re-imaged back to 10 and was offered the upgrade in Windows Update on 20th October. Windows Update offered the 22H2 Feature Update on 20th September 2022. It got the 23H2 Feature Update on 4th November 2023 through Windows Update.

    My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB ssd, supported device running Windows 11 Pro (and all my Hyper-V VMs).

    My SYSTEM FOUR is a 2-in-1 convertible Lenovo Yoga 11e 20DA, Celeron N2930, 4GB RAM, 256GB ssd. Unsupported device: currently running Win10 Pro, plus Win11 Pro RTM and Insider Beta as native boot vhdx.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 4GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro, plus the Insider Beta, Dev, and Canary builds as a native boot .vhdx.
  • Operating System
    Windows 11 Pro
    Computer type
    Laptop
    Manufacturer/Model
    Dell Lattitude E4310
    CPU
    Intel® Core™ i5-520M
    Motherboard
    0T6M8G
    Memory
    8GB
    Graphics card(s)
    (integrated graphics) Intel HD Graphics
    Screen Resolution
    1366x768
    Hard Drives
    500GB Crucial MX500 SSD
    Browser
    Firefox, Edge
    Antivirus
    Defender
    Other Info
    unsupported machine: Legacy bios, MBR, TPM 1.2, upgraded from W10 to W11 using W10/W11 hybrid install media workaround. In-place upgrade to 22H2 using ISO and a workaround. Feature Update to 23H2 by manually installing the Enablement Package.

    My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB ssd, supported device running Windows 11 Pro (and all my Hyper-V VMs).

    My SYSTEM FOUR is a 2-in-1 convertible Lenovo Yoga 11e 20DA, Celeron N2930, 4GB RAM, 256GB ssd. Unsupported device: currently running Win10 Pro, plus Win11 Pro RTM and Insider Beta as native boot vhdx.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 4GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro, plus the Insider Beta, Dev, and Canary builds as a native boot .vhdx.
That's odd, your processor isn't on the MS list here:
maybe MS have now added it to the supported processors, but not got round to updating their documentation yet.

Well, if your motherboard has a UEFI bios and a lack of Secure Boot with a GPT disk is your only impediment, then it is possible to convert a Legacy/MBR install to UEFI/GPT without data loss. Be sure to make a system image with something like Macrium Reflect Free before you try though.


Will that work even though my boot partition and system partition are on different disks? That's the issue I've encountered.
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB
Will that work even though my boot partition and system partition are on different disks? That's the issue I've encountered.
That's just making life complicated for yourself :wink:

@NavyLCDR is more knowledgeable about such things than I am, he may be able to help.
 

My Computers

System One System Two

  • OS
    Windows 11 Home
    Computer type
    Laptop
    Manufacturer/Model
    Acer Aspire 3 A315-23
    CPU
    AMD Athlon Silver 3050U
    Memory
    8GB
    Graphics Card(s)
    Radeon Graphics
    Monitor(s) Displays
    laptop screen
    Screen Resolution
    1366x768 native resolution, up to 2560x1440 with Radeon Virtual Super Resolution
    Hard Drives
    1TB Samsung EVO 870 SSD
    Internet Speed
    50 Mbps
    Browser
    Edge, Firefox
    Antivirus
    Defender
    Other Info
    fully 'Windows 11 ready' laptop. Windows 10 C: partition migrated from my old unsupported 'main machine' then upgraded to 11. A test migration ran Insider builds for 2 months. When 11 was released on 5th October it was re-imaged back to 10 and was offered the upgrade in Windows Update on 20th October. Windows Update offered the 22H2 Feature Update on 20th September 2022. It got the 23H2 Feature Update on 4th November 2023 through Windows Update.

    My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB ssd, supported device running Windows 11 Pro (and all my Hyper-V VMs).

    My SYSTEM FOUR is a 2-in-1 convertible Lenovo Yoga 11e 20DA, Celeron N2930, 4GB RAM, 256GB ssd. Unsupported device: currently running Win10 Pro, plus Win11 Pro RTM and Insider Beta as native boot vhdx.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 4GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro, plus the Insider Beta, Dev, and Canary builds as a native boot .vhdx.
  • Operating System
    Windows 11 Pro
    Computer type
    Laptop
    Manufacturer/Model
    Dell Lattitude E4310
    CPU
    Intel® Core™ i5-520M
    Motherboard
    0T6M8G
    Memory
    8GB
    Graphics card(s)
    (integrated graphics) Intel HD Graphics
    Screen Resolution
    1366x768
    Hard Drives
    500GB Crucial MX500 SSD
    Browser
    Firefox, Edge
    Antivirus
    Defender
    Other Info
    unsupported machine: Legacy bios, MBR, TPM 1.2, upgraded from W10 to W11 using W10/W11 hybrid install media workaround. In-place upgrade to 22H2 using ISO and a workaround. Feature Update to 23H2 by manually installing the Enablement Package.

    My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB ssd, supported device running Windows 11 Pro (and all my Hyper-V VMs).

    My SYSTEM FOUR is a 2-in-1 convertible Lenovo Yoga 11e 20DA, Celeron N2930, 4GB RAM, 256GB ssd. Unsupported device: currently running Win10 Pro, plus Win11 Pro RTM and Insider Beta as native boot vhdx.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 4GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro, plus the Insider Beta, Dev, and Canary builds as a native boot .vhdx.
That's just making life complicated for yourself :wink:

@NavyLCDR is more knowledgeable about such things than I am, he may be able to help.

Haha, I know. Hey, if he's a Navy Lt. Commander I'm sure he can help. I'm former Navy myself!

Here is what happens when I try the conversion. That error window always pops up too:

IMG_0288.PNG
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB
Hi,

I had the same problem (WIN 10 / WIN 11 dual boot on 2 disks (!), not partitions (!)). I made backups with Macrium Backup, after having converted both disks from MBR to GPT / EFI (with the mbr2gpt tool which is in Windows as explained in the link above), I made backups with Macrium, but Macrium copied only 2 partitions from the first disk and NOT the WIN 11 partition I wanted to backup (and which was on the second disk).

But there is a tool in Macrium which (in my opinion) could resolve this. After installing Macrium, go to "Rescue" (upper left icon in the macrium window) and run it. It copied the two partition which were on the wrong disk to the right one (but not the "System reserved partition, which apparently is not necessary). (You then need to restart the computer).

When you then make the backup, please pay attention that the "hooks" before the partitions to be copied are all on the same disk (Macrium seems to prefer to backup the "originals" on the other disk and not the "copies" on the same disk.

I cannot garantee the outcome, because I had more partitions on my disk than you, but just try it. Macrium is free !
 

My Computer

System One

  • OS
    WIN 11 / WIN 10 dual boot
    Computer type
    PC/Desktop
    Manufacturer/Model
    No clue (x64 based) from 2016
    CPU
    Intel Pentium G 4400 (Skylake)
    Motherboard
    MS 7971, Bios: American Megatrend C.E0 (2018)
    Memory
    DDR4 12 GB
    Graphics Card(s)
    internal (Intel HD 510)
    Hard Drives
    2x Western Digital (no SSD)
Hi,

I had the same problem (WIN 10 / WIN 11 dual boot on 2 disks (!), not partitions (!)). I made backups with Macrium Backup, after having converted both disks from MBR to GPT / EFI (with the mbr2gpt tool which is in Windows as explained in the link above), I made backups with Macrium, but Macrium copied only 2 partitions from the first disk and NOT the WIN 11 partition I wanted to backup (and which was on the second disk).

But there is a tool in Macrium which (in my opinion) could resolve this. After installing Macrium, go to "Rescue" (upper left icon in the macrium window) and run it. It copied the two partition which were on the wrong disk to the right one (but not the "System reserved partition, which apparently is not necessary). (You then need to restart the computer).

When you then make the backup, please pay attention that the "hooks" before the partitions to be copied are all on the same disk (Macrium seems to prefer to backup the "originals" on the other disk and not the "copies" on the same disk.

I cannot garantee the outcome, because I had more partitions on my disk than you, but just try it. Macrium is free !

I installed the free version of Macrium Reflect 7. I don't see a "Rescue" option. There is a Restore option, and under Other Tasks there is "Create Rescue Media".
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB
I installed the free version of Macrium Reflect 7. I don't see a "Rescue" option. There is a Restore option, and under Other Tasks there is "Create Rescue Media".
You need to make the Macrium rescue media USB and boot from that to see operations that can only be carried out while the system is not running. One such option that's only available when booted form a recovery USB is 'fix Windows boot problems' on the 'Restore' menu.
 

My Computers

System One System Two

  • OS
    Windows 11 Home
    Computer type
    Laptop
    Manufacturer/Model
    Acer Aspire 3 A315-23
    CPU
    AMD Athlon Silver 3050U
    Memory
    8GB
    Graphics Card(s)
    Radeon Graphics
    Monitor(s) Displays
    laptop screen
    Screen Resolution
    1366x768 native resolution, up to 2560x1440 with Radeon Virtual Super Resolution
    Hard Drives
    1TB Samsung EVO 870 SSD
    Internet Speed
    50 Mbps
    Browser
    Edge, Firefox
    Antivirus
    Defender
    Other Info
    fully 'Windows 11 ready' laptop. Windows 10 C: partition migrated from my old unsupported 'main machine' then upgraded to 11. A test migration ran Insider builds for 2 months. When 11 was released on 5th October it was re-imaged back to 10 and was offered the upgrade in Windows Update on 20th October. Windows Update offered the 22H2 Feature Update on 20th September 2022. It got the 23H2 Feature Update on 4th November 2023 through Windows Update.

    My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB ssd, supported device running Windows 11 Pro (and all my Hyper-V VMs).

    My SYSTEM FOUR is a 2-in-1 convertible Lenovo Yoga 11e 20DA, Celeron N2930, 4GB RAM, 256GB ssd. Unsupported device: currently running Win10 Pro, plus Win11 Pro RTM and Insider Beta as native boot vhdx.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 4GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro, plus the Insider Beta, Dev, and Canary builds as a native boot .vhdx.
  • Operating System
    Windows 11 Pro
    Computer type
    Laptop
    Manufacturer/Model
    Dell Lattitude E4310
    CPU
    Intel® Core™ i5-520M
    Motherboard
    0T6M8G
    Memory
    8GB
    Graphics card(s)
    (integrated graphics) Intel HD Graphics
    Screen Resolution
    1366x768
    Hard Drives
    500GB Crucial MX500 SSD
    Browser
    Firefox, Edge
    Antivirus
    Defender
    Other Info
    unsupported machine: Legacy bios, MBR, TPM 1.2, upgraded from W10 to W11 using W10/W11 hybrid install media workaround. In-place upgrade to 22H2 using ISO and a workaround. Feature Update to 23H2 by manually installing the Enablement Package.

    My SYSTEM THREE is a Dell Latitude 5410, i7-10610U, 32GB RAM, 512GB ssd, supported device running Windows 11 Pro (and all my Hyper-V VMs).

    My SYSTEM FOUR is a 2-in-1 convertible Lenovo Yoga 11e 20DA, Celeron N2930, 4GB RAM, 256GB ssd. Unsupported device: currently running Win10 Pro, plus Win11 Pro RTM and Insider Beta as native boot vhdx.

    My SYSTEM FIVE is a Dell Latitude 3190 2-in-1, Pentium Silver N5030, 4GB RAM, 512GB NVMe ssd, supported device running Windows 11 Pro, plus the Insider Beta, Dev, and Canary builds as a native boot .vhdx.
You need to make the Macrium rescue media USB and boot from that to see operations that can only be carried out while the system is not running. One such option that's only available when booted form a recovery USB is 'fix Windows boot problems' on the 'Restore' menu.

Ah, OK. I'll have to look into that later.
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB
NapMan, because you already have installed Macrium Reflect, it would be wise to start from creating the backup of your current not converted OS drive. Looking at the error at your first attempt, the second one may make the drive non-operative, so your backup copy will be very useful. Of course I wish it's not your case, but anyway, an extra backup on removable drive is never excessive. You may easily delete it after conversion to UEFI when you made another backup of working OS.

And if you will have continuous problem with conversion, it's possible to install Windows 11 on MBR, even though it's officially counted non-supported configuration. You can convert the drive in Windows 11 later or keep it for a while, at least now "unsupported" PCs are still supported, they all got the last Tuesday update.
 

My Computer

System One

  • OS
    Windows 11 Pro; Windows 8.1 Pro
    Computer type
    PC/Desktop
    CPU
    i7-12700K (Alder Lake)
    Motherboard
    Asus PRIME Z690-M Plus D4
    Memory
    16 GB (2x8 Corsair DDR4-2132)
    Graphics Card(s)
    Asus GeForce 1050 Ti, 4 GB
    Monitor(s) Displays
    Philips 235PQ
    Screen Resolution
    1920x1080
    Hard Drives
    Windows 11: Samsung SSD 870 EVO, 500 GB (SATA), MBR
    Windows 8.1: Samsung SSD 980 PRO, 500 GB (M.2), MBR
    PSU
    Platimax D.F. 1050 W (80 Plus Platinum)
    Internet Speed
    Local link 1 Gbps, provider's line 500 Mbps
    Browser
    Google Chrome
    Other Info
    Realtek PCIe GbE Family Controller (for Windows 8.1 compatibility)
    Microsoft Office H&S 2013 x64
I cannot convert it because my boot partition and system partition are on different disks
Part of the problem is that your OS disk (disk 1) has no space on it for the System Reserved partition. You would need to first shrink the OS partition to create space.
Then, if you disconnect disk 0 from the power, the computer will think it has no MBR so you manually create a new System Reserved partition on the OS disk, and then rebuild the MBR.
When finished, you will have an OS partition with System Partition on the same disk.

Use a Recovery disk or an Installation disk to boot the computer without the MBR, and enter the command prompt from that environment.

How to Manually Rebuild the MBR System Reserved partition, follow this tutorial:

If you're starting with no system partition
The first thing we need to do is to create our system partition
At the command prompt type the following.
  • Type diskpart
  • Type list disk
  • If you only have 1 disk then type select disk 0
  • If you have multiple disks, you will want to select each in turn and type detail disk to identify the correct disk. Most of the time you will have the system partition on the same drive as the C volume. Typing detail disk will show you what volumes are on the selected disk

  • Now create the partition with create part primary
  • Type list part and ID the newly created partition. (If the system partition was deleted the new partition will be the same size and less than 1GB)
  • Now select the partition with select part # where # will be the number identified from the list command
  • With the new partition selected mark it active by typing active
  • Now format the partition with format fs=ntfs quick label="System Reserved"
  • Type list vol and make note of your new partition
  • Type select vol # where the # is the number assigned to your volume
  • Type assign letter E the letter can be any non-assigned drive letter (we'll need this in a later step, also make note of your OS assigned letter [it might not be C])
  • We're all done preparing the disk so type exit
If the system partition exists and you just cant boot start here (continue with the next section)
Now it's time to prepare or repair the system partition
  • First we need to make sure the system partition has a valid MBR on it by typing bootrec /fixmbr
  • Now we need to copy critical system files and BCD store. From my example above my system partition is E and my OS is C type the following bcdboot C:\Windows /s e:
With a rebuilt MBR on the new System Reserved partition, you can then proceed conversion to GPT.

Hope that helps
 

My Computers

System One System Two

  • OS
    Windows 11
    Computer type
    PC/Desktop
    CPU
    AMD Ryzen 5 5600
    Motherboard
    MSI B550-A Pro
    Memory
    16 GB
    Graphics Card(s)
    Sapphire Radeon RX 6500XT (8 GB version)
    Monitor(s) Displays
    BenQ Mobuiz EX2710Q QHD, Iiyama ProLite X23377HDS
    Hard Drives
    MSI Spatium M461 4TB
  • Operating System
    Windows 11
    Computer type
    Laptop
    Manufacturer/Model
    Acer A114
    CPU
    Intel Celeron N4020
NapMan, because you already have installed Macrium Reflect, it would be wise to start from creating the backup of your current not converted OS drive. Looking at the error at your first attempt, the second one may make the drive non-operative, so your backup copy will be very useful. Of course I wish it's not your case, but anyway, an extra backup on removable drive is never excessive. You may easily delete it after conversion to UEFI when you made another backup of working OS.

And if you will have continuous problem with conversion, it's possible to install Windows 11 on MBR, even though it's officially counted non-supported configuration. You can convert the drive in Windows 11 later or keep it for a while, at least now "unsupported" PCs are still supported, they all got the last Tuesday update.

I will make a backup before I do anything. Thanks for the suggestion.
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB
Part of the problem is that your OS disk (disk 1) has no space on it for the System Reserved partition. You would need to first shrink the OS partition to create space.
Then, if you disconnect disk 0 from the power, the computer will think it has no MBR so you manually create a new System Reserved partition on the OS disk, and then rebuild the MBR.
When finished, you will have an OS partition with System Partition on the same disk.

Use a Recovery disk or an Installation disk to boot the computer without the MBR, and enter the command prompt from that environment.

How to Manually Rebuild the MBR System Reserved partition, follow this tutorial:


With a rebuilt MBR on the new System Reserved partition, you can then proceed conversion to GPT.

Hope that helps

Maybe I don't fully understand. When you say the "system reserved partition", is that not the 50 MB partition on Disk 0? The boot disk has 28 GB free.
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB
Maybe I don't fully understand. When you say the "system reserved partition", is that not the 50 MB partition on Disk 0? The boot disk has 28 GB free.
Yes, I meant the 50 MB partition on Disk 0. That is the partition you are trying to move/recreate on the OS disk (Disk 1)?

The "boot disk", or rather the "OS partition" on disk 1, has 28GB free, but this is not useable in a scenario where you are re-creating the MBR on disk 1. That 28GB is only useable to the C: partition, so you would need free up some disk space by shrinking the C: partition.

That is just my suggestion, anyway.
 

My Computers

System One System Two

  • OS
    Windows 11
    Computer type
    PC/Desktop
    CPU
    AMD Ryzen 5 5600
    Motherboard
    MSI B550-A Pro
    Memory
    16 GB
    Graphics Card(s)
    Sapphire Radeon RX 6500XT (8 GB version)
    Monitor(s) Displays
    BenQ Mobuiz EX2710Q QHD, Iiyama ProLite X23377HDS
    Hard Drives
    MSI Spatium M461 4TB
  • Operating System
    Windows 11
    Computer type
    Laptop
    Manufacturer/Model
    Acer A114
    CPU
    Intel Celeron N4020
Yes, I meant the 50 MB partition on Disk 0. That is the partition you are trying to move/recreate on the OS disk (Disk 1)?

The "boot disk", or rather the "OS partition" on disk 1, has 28GB free, but this is not useable in a scenario where you are re-creating the MBR on disk 1. That 28GB is only useable to the C: partition, so you would need free up some disk space by shrinking the C: partition.

That is just my suggestion, anyway.

I appreciate your help. I guess I don't really understand freeing up disk space on the C: partition by shrinking the C: partition. If I make the C: partition smaller wouldn't that create less free space?
 

My Computer

System One

  • OS
    Windows 10
    CPU
    AMD Ryzen 5 1600, 6-core, 3200Mhz
    Motherboard
    Asus B450M-A
    Memory
    16 GB

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