Windows 10: If you install Windows does it install the EFI system partition?

Say you buy Windows 10 from Amazon. When installing, does Windows 10 also install the EFI system partition? If not how do you get that partition installed on a new drive?

:)

 

It will cost you 100 GBP if you install win 10 from ISO instead of waiting for upgrade download.

What happened to the free upgrade promised. Used Msofr media to download and produce an ISO which when installed will cost 100 GBP to activate, no warnings given that this will wipe your old system product key and you will not be able to revert back to old
op system.

Msoft at its best or worst depending.

 

Always booting from the wrong drive

The presence of the EFI System and MSR reserved partitions on the old install means it's a UEFI install to GPT disk. When you installed to the new disk it used the existing EFI System partition to Dual Boot so that when it was detached the new install cannot
boot. Had you not wanted the old install you should have unplugged it's drive during install. If you did anything else like installed the new Windows in Compatibility mode please advise.

Now if this were the Legacy BIOS with an MBR disk we could simply mark the new install's partition Active and run a few Startup Repairs or Rebuild the BCD to get it booting. But for UEFI there must be at least the EFI System partition to boot it. You
can create one by shrinking the Windows partition from the left by a minimum 500mb I'd recommend.

Then try either a bootable partition Manager or Diskpart from the Command Prompt of the booted Windows media to create the EFI System partition:

Create EFI System Partition in Easy Steps to Make Windows Bootable Again

Restore/Repair Deleted EFI Boot Partition in Windows 10/8/7 – EaseUS

If you can create it but it still won't boot then try a Startup Repair, or
Rebuild the BCD in Windows [10 to 20 Minutes] as a last resort to export
and rebuild which often works. **Note that the commands given to copy boot files must reference the EFI System partition and not Windows partition.

When doing these operations unplug all other physical drives. Plug the target Windows drive into SATA 1 which should be DISK 0.

 

Yes, Windows creates this partition as part of the installation process. If your PC was made after about 2007 it will have a UEFI option in the Boot Menu section of the BIOS. This must be selected before starting the installation.

 

Thanks very much. I would not have known to select an option in the BIOS

 

You're welcome. You need to check for this as Windows may be installed as the old MBR/BIOS based system if this is how it was setup at the factory.

 

And also check the mode the SATA disk drive interfaces are set for. You want AHCI mode before you begin the Windows 10 install.

 

Exactly, yes....i forgot to include that!

 

If, for some reason, you did get a PC on which someone installed W10 using Legacy mode on a MBR drive, you would not have that partition.

And there would be no reason to want to try to create it.

It`s only created when you install windows using UEFI on a GPT disk.

Research, Research, Research *Smile

 

This is a brand new build

 

Is there some problem ?

 

If legacy BIOS setting of off, it will install as UEFI. If legacy setting is on, boot menu will give you a choice between UEFI and normal MBR. If you don't go through boot menu, I think it's like random selection.
If you have an older motherboard, it will install as normal MBR.
For windows 32-bit, it's normal MBR, unless you have one of the special 32-bit UEFI firmware/BIOS. I've seen few.

You can move between MBR and UEFI/GPT easily using Macrium software. I've done it many times.
Restoring a UEFI/GPT System image to MBR - KnowledgeBase - Macrium Reflect Knowledgebase
How to Restore an MBR System image to UEFI/GPT (Convert, GPT, MBR, Restore)

You can move between AHCI and IDE by booting from a separate SATA controller card, then changing the BIOS and drivers. Or the hard way by changing the device ID in registry or something like that, which I've done few times.

 

There is no need to boot from a separate SATA controller card. Boot Windows into safe mode. Uninstall the PCI drive controller from Device Manager. Reboot the computer into BIOS/UEFI settings. Change the controller mode from PCI to AHCI. Reboot back into Windows Safe Mode. Turn off Safe Mode. Reboot computer into normal Windows.