Windows 10: Installed Windows 11 on a new drive, but boot manager stayed on old drive. Creating new EFI...

Good morning!My system is composed of 3 drives: Drive 0 - data driveDrive 1 - older drive where i had originally installed windows 10Drive 2 - new drive, with installed windows 11The installation of windows 11 went through without errors, and the dual boot between windows 10-11 works well.Now I would like to format completely Drive 1, to use it as secondary data drive, and keep only windows 11.Drive 1 has the boot manager partition from what i can see, so i am afraid that by formatting the drive i would break windows 11 too.The image below shows my current state. I tried to manually create a 5

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old (empty) M.2 drive is still the boot drive

Hi MikeE1067,

I am Dave, I will help you with this.

There is a bug in the Windows installation process, during the installation, if another drive is still connected that had a Windows installation, a new boot partition is not created on the new drive, it will still use the boot partition on the old drive.

Right click your Start Button, and open Disk Management form the resulting menu

In the bottom pane, look at the two drives, is the small EFI (boot) partition on the old drive and none on the new drive?

If that is the case, you will need to re-install Windows on the new SSD and disconnect the old drive before the installation

If you are unsure, please provide a screenshot of the Disk Management window showing both drives in the bottom pane.

 

Move Windows EFI boot partition to another drive.

I have a Windows installation with three drives

C:\ (windows 10 installation)

E:\ (stuff)

D:\ (contains the EFI boot partition + stuff)

For what ever reason, when i installed Windows with a two disk setup, the core installation was installed on C:\ and the EFI partition was installed on D:\

I no longer need drives E:\ and D:\, but i cannot remove D:\ because this contains the EFI boot partition and the system cannot boot without it.

But i also don't want to keep a 450GB SSD just to save a 100MB EFI boot partition onto it.

So my question is.

Q1: How can i move the EFI partition?

Answer: I have already gone to my C:\ with disk manager and shrinked the partition by 110 MB, going into CMD (as administrator) and with the commands

$ diskpart

$ list

$ select disk 3

$ create partition efi

$ exit

The above created a new EFI partition on the C:\ drive on the 110 MB partition.

Q2: How do i get Windows to use the new EFI partition so i can physically remove the D:\ drive?

Thank you in advance

Best regards.

 

Need help installing a new hard drive

yes, so just unplug the old hard drive and install windows onto the new drive, it being the only drive plugged into the computer.
then after windows is installed and it works, plug the old one back in and it will be recognized. obviously turn the computer off while plugging in/out drives.

you only had to go to computer management if you needed to see the drive in windows, if you want to install a fresh install of windows to the drive and then use both afterward (recommended) then this will do it.

if , by chance, it boots the old windows instead of the new after doing that - then just go into the bios and arrange the drives in your boot priority, putting the new drive first.