Partitions Wrong Format : use BIOS instead of UEFI ?

[Fred371]

First let me describe what is the good news from my point of view and I will EVENTUALLY end up saying what my problem is.

I have an 8200 desktop and I want to load Windows 10 onto it via a USB stick.
( The reason I need to do this is another story which I very much hope I will not have to tell. )

1. I did get Microsoft’s own ‘Media Creation Tool’ which takes an iso of Windows 10 and wraps software around it to do the loading.

2. I did use the Esc button when switching on the desktop to give me various options at boot time.

3. I did manage to change the boot priority so that the flash drive is now the first place to look for an OS
( despite there being no option as obvious as ‘USB Drive’. )

4. I did manage to get the Windows 10 logo and answer a few questions ( such as accepting a EULA ).

5. The problem arose when I got to the screen asking me to choose the partition where the OS should go.
I did choose the largest, obviously enough but each partition generated the same message :
something about the formatting of the partition being incorrect.

From what little else I know, I think this has something to do with the fact that I am loading via UEFI rather than BIOS,
in which case my question becomes :

how exactly do I ‘Enable BIOS’ in this context ? I have moved around the various options available here

including a Windows Command Prompt window. Would THAT help ?

Thanks in advance for your help.

[WAWood · Accepted solution]

@Fred371 

There are two different MODES for loading/installing Win10 -- UEFI and BIOS.  The first expects partitions to be formatted using GPT; the second expects them to be formatted using MBR.  These are not interchangeable.

HP PCs that come preloaded with Win10 use UEFI-GPT formatting not BIOS-MBR formatting.  So to reload the PS, you need to use the same mode and formatting.

IF you boot using UEFI mode installer and it sees MBR-formatted partitions, it will not install.  So if you are using a UEFI-GPT Win10 installer and it is complaining about the existing partitions, then Win10 must have been installed using BIOS-MBR.

You can address that by recreating the Win10 install media to use BIOS-MBR instead of UEFI.

[Fred371]

You can address that by recreating the Win10 install media to use BIOS-MBR instead of UEFI.

As I remember it  Windows Media Creation tool did NOT give  options  there.

Should I use something else such as Rufus ?

[Fred371]

• 
  Since I made my previous post I have now seen YouTube videos discussing this very problem.

  On the screen I have problems with hit Shift+F10 which opens a Windows Command Prompt window.

  Key :

  • DISKPART ;
  • list disk;
  • select disk 1 ( for instance ) ;
  • clean;
  • convert mbr

  Do you agree ?