UEFI/GPT Windows 10 fresh install, some questions on diskpart and ESP

I would like to clean(fresh) install Windows 10 on a machine that in the end will be split in two partitions to host 2 x Windows 10 Professional.

I want to opt for UEFI + GPT.

I was reading that a GPT disk must have a special system partition known as the ESP (EFI System Partition). My question is: do I have to create this myself using diskpart or it gets created automatically?

The notes I have on diskpart are:

Code:

diskpart
list disk
select disk 0
list partition
clean
list partition (to confirm all partitions have been removed)
convert gpt (only if list disk had no asterisk)
create partition primary size=153600 align=1024
format quick fs=ntfs label="First Partition"
active
exit
exit

Is the above enough or I have to change to this?

Code:

diskpart
list disk
select disk 0
list partition
clean
list partition (to confirm all partitions have been removed)
convert gpt (only if list disk had no asterisk)
create partition efi size=100
format quick fs=fat32 label="System"
create partition msr size=16
create partition primary size=153600 align=1024
format quick fs=ntfs label="First Partition"
active
exit
exit

This will result in something like this: https://itknowledgeexchange.techtarg...aller-view.png - this is from this guide I found via Google: Partition UEFI/GPT HDD Using Diskpart - Windows Enterprise Desktop

The easiest way to do what you want to do is to just do a clean install to a completely clean disk with no partitions on it - 100% unallocated space. Windows setup will create the ESP (EFI System Partition) for you. Then shrink the OS partition that is created by the amount you want the second OS to have. Create a partition for the second OS, format it as NTFS. The run Windows setup again and this time select the second partition that you created to install to. Windows setup will set up dual booting for you.

NavyLCDR said:

The easiest way to do what you want to do is to just do a clean install to a completely clean disk with no partitions on it - 100% unallocated space.

I understand, apologies for maybe repeating what you just said but I want to be sure.

So diskpart steps should change to:

diskpart
list disk
select disk 0
clean
create partition primary align=1024
format quick fs=ntfs
active
exit
exit

I would then install Windows in the only partition of the drive, the installation will take care of ESP or any other needed system partitions.

And then after Windows is all set up, in My Computer > Manage > Disk Management, rather than selecting the unallocated space and choose "New Simple Volume"(since I specified no size in diskpart), I should instead shrink the drive and proceed with the 2nd Windows installation either via the USB drive I used for the first partition or else using dism: Dual Boot Win 10 to Win 10

The OP need not use DiskPart but may want to know how to use it.
I used DiskPart to reformat and repartition my HDD before clean installing Windows 10.

tenuser1967 said:

I understand, apologies for maybe repeating what you just said but I want to be sure.

No, what I stated was to install Windows 10 first to a completely empty, 100% unallocated drive:



After you get the first Windows 10 installed, then you can shrink the C: drive partition (disk management is one way), then create a new simple volume in the unallocated space, format that as NTFS, then do Windows setup again, but this time install to the new partition that you created.

Is there a specific reason that you must create partitions first with diskpart?

tenuser1967 said:

I would like to clean(fresh) install Windows 10 on a machine that in the end will be split in two partitions to host 2 x Windows 10 Professional.

What are the sizes of the two partitions?

In my following example, the 81-GB space was for Windows 10.

tenuser1967 said:

This time around the drive will be 100% new(SSD).

Then don't do anything at all to the new drive. Just boot the computer from a Windows 10 installation USB flash drive in UEFI mode and install the first Windows 10 to the completely blank, unallocated SSD.