Win11 USB install problem, MBR problem

Hi all- two minute history as follows. Had a dual boot Ubuntu/Win11 on a small Costco HP box. Attempted to remove the Ubuntu side and, well, here I am.

Machine has a 250ssd and 500 data drive. Trying to install Win11 via USB to the SSD. Get the warning selected disk has MBR table. Used diskpart to clean, convert gpt but I still get the MBR error window? Any help greatly appreciated.

Mark

Make sure to enable UEFI mode in BIOS.

Newtie said:

Hi all- two minute history as follows. Had a dual boot Ubuntu/Win11 on a small Costco HP box. Attempted to remove the Ubuntu side and, well, here I am.

Machine has a 250ssd and 500 data drive. Trying to install Win11 via USB to the SSD. Get the warning selected disk has MBR table. Used diskpart to clean, convert gpt but I still get the MBR error window? Any help greatly appreciated.

Click to expand...

It's best to clean install after backing up important files:

FreeBooter said:

Make sure to enable UEFI mode in BIOS.

Click to expand...

It’s enabled, I checked that prior to my attempted install.

zbook said:

It's best to clean install after backing up important files:

Clean Install Windows 11

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Download Official Windows 11 ISO file from Microsoft

This tutorial will show you how to download an official Windows Server or Windows 11 64-bit or ARM64 ISO file from Microsoft. Microsoft provides ISO files for Windows Server and Windows 11 to download. You can use these ISO files to clean install or in-place upgrade Windows 11. The Flight Hub...

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Download Windows 11

Click to expand...

Both disks are wiped, no files are present.
I looked at the Clean install of Win 11 and there’s no reference to the repeated MBR error I’m getting.

Windows can be installed in two ways: Legacy-MBR or UEFI-GPT
To install as Legacy-MBR you must boot the installation drive as Legacy
To install as UEFI-GPT you must boot the installation drive as UEFI.

As you have a UEFI BIOS, you should install as UEFI-GPT
Detach any other drives (SATA or Power cable) from the MB.

During POST, press F12(?) to launch the boot menu. You will see two options for the USB drive. USB UEFI (Name) and USB (Name). Select USB UEFI (Name) to install as UEFI-GPT.
Go to install and delete ALL partitions on the main drive till you have one and only one unallocated space and then proceed.

Megahertz said:

Windows can be installed in two ways: Legacy-MBR or UEFI-GPT
To install as Legacy-MBR you must boot the installation drive as Legacy
To install as UEFI-GPT you must boot the installation drive as UEFI.

As you have a UEFI BIOS, you should install as UEFI-GPT
Detach any other drives (SATA or Power cable) from the MB.

During POST, press F12(?) to launch the boot menu. You will see two options for the USB drive. USB UEFI (Name) and USB (Name). Select USB UEFI (Name) to install as UEFI-GPT.
Go to install and delete ALL partitions on the main drive till you have one and only one unallocated space and then proceed.

Click to expand...

Yes. If he follows your advice, it should work.

Very important to boot the usb drive in uefi mode, not mbr.

I did this a few years ago on a very old Dell machine built in 2012. I did it in stages because I am cautious. First, I used mbr2gpt, but It only worked for me when I did this offline when windows wasn't running. It failed if I tried while windows 10 was running.

Then, I changed bios settings to uefi. Every time I made a change, I rebooted and tested with my existing windows 10 system to be assured it was working. Finally, I had the machine booting uefi with all drives in gpt format. Then I took the plunge to win 11.

And I also had a macrium reflect backup image, in case there was a disaster.

I am still using this ancient machine today, and in fact posting this with it now, several years later :)

Newtie said:

Hi all- two minute history as follows. Had a dual boot Ubuntu/Win11 on a small Costco HP box. Attempted to remove the Ubuntu side and, well, here I am.

Machine has a 250ssd and 500 data drive. Trying to install Win11 via USB to the SSD. Get the warning selected disk has MBR table. Used diskpart to clean, convert gpt but I still get the MBR error window? Any help greatly appreciated.

Mark

Click to expand...

Read Megahertz's post. It is pretty detailed. I'll add that it may be better to use the microsoft program "mbr2gpt" to convert your drive to gpt, but it works best in offline mode. And you MUST boot your flash install drive in uefi mode. Otherwise, it will stick to mbr.

8

Megahertz said:

Windows can be installed in two ways: Legacy-MBR or UEFI-GPT
To install as Legacy-MBR you must boot the installation drive as Legacy
To install as UEFI-GPT you must boot the installation drive as UEFI.

As you have a UEFI BIOS, you should install as UEFI-GPT
Detach any other drives (SATA or Power cable) from the MB.

During POST, press F12(?) to launch the boot menu. You will see two options for the USB drive. USB UEFI (Name) and USB (Name). Select USB UEFI (Name) to install as UEFI-GPT.
Go to install and delete ALL partitions on the main drive till you have one and only one unallocated space and then proceed.

Click to expand...

Hey Megahertz- thanks for this. What fixed it was downloading and installing the original storage drivers and deleting all partitions on the SSD which resulted in the unallocated space you mentioned. I'm installed and downloading all the updates as we speak. Appreciate all the help from everyone here. I'm not going to say how long I've been working on this