Installing UEFI or EFI windows 10 is much complicated if once EFI partition deleted.

Question

Installing UEFI or EFI windows 10 is much complicated if once EFI partition deleted.

Anonymous

There were some errors on old windows 10, the time I was working to fix the errors using Recovery mode Command Prompt I used command 'Clean' on windows disk I was to plan a new install.

I was unaware about the problems if once the EFI partition is deleted this is going very hard task to install windows EFI (non CSM) again.

Spent hours of reading and practical but no success in installing windows EFI.

There should be a tool from Microsoft to fix this complication.

When I select in my BIOS EFI (non CSM) the boot manger stuck with a dialogue displaying 2 disks (flashdriver + system disk) all we can do is press 'Tab' and select Enter Setup. No success to move advance from this step, no wonder whatever I did. A flash drive with small Linux distro is booting fine, Window 10 MBR booting fine. When it comes to EFI just stuck on boot manager. Even tried to boot with EFI Shell the latest version from Rufus GitHub but that also stuck on boot manger.

I have tried most of stuff advised on answers.microsoft.com. Include following.

1-MBR Windows installed, converting disk format to GPT from command prompt in recovery mode.

2-Creating new EFI Partition 100mb, creating new MSR Partition 16mb, Rebuilding BCD using command.

3-Set in BIOS = EFI non CSM. Restart and Boot Manager again kind of freezed. No accepting the EFI windows installer flashdrive to boot, not accepting the already installed windows with GPT partition format, EFI partition, BCD, MSR partition.

Kindly Assist what I am missing.

Used troubleshoot>command prompt.

Following is system information: Ask me if anything further required.

OS Name Microsoft Windows 10 Pro

Version 10.0.19045 Build 19045

System Type x64-based PC

Processor Intel(R) Core(TM) i7-4610M CPU @ 3.00GHz, 3001 Mhz, 2 Core(s), 4 Logical Processor(s)

BIOS Version/Date Phoenix Technologies Ltd. R1.02.060101, 9/2/2019

SMBIOS Version 2.7

Embedded Controller Version 1.00

BIOS Mode Legacy

Platform Role Mobile

Secure Boot State Unsupported

Hardware Abstraction Layer Version = "10.0.19041.3636"

Installed Physical Memory (RAM) 16.0 GB

System Manufacturer GETAC

System Model X500G2

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4 answers

Answer 1

Hi, Wicky,

Sorry to hear you're experiencing this issue.

Creating the Windows installation media in the UEFI mode using the Rufus app will install Windows in the UEFI mode.

Using another computer

Step 1: Download the Windows ISO

1-Download and execute the Media Creation tool.

https://go.microsoft.com/fwlink/?LinkId=691209

2-On the What do you want to do? page, select Create installation media for another PC, and then select Next.

3-Select ISO file. Save an ISO file to your PC

Step 2: Create the bootable USB

1-Download and execute the Rufus app

https://github.com/pbatard/rufus/releases/downl...

Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.

2-In the Device, select the flash drive that you want to use

3-Then click on the Select button and select the Windows ISO download in the previous step

4-Then make sure that all other options are like in the image below and click on the Start button

5-Wait until finished

Step 3: Change your Bios settings to UEFI and disable the "CSM".

Step 4: Boot from the flash drive and proceed with the Windows installation.

I hope this information helps. If you have any questions or the problem persists, please let me know and I'll be glad to assist you further.

Answer 2

Please provide some more information to help identify what is causing the problem.

-Attach a photo of the first screen of the Bios settings and a photo of the boot settings screen.

-Attach a screenshot of the result of these commands.

1-Boot from the flash drive

2-On the installation screen click on "Repair your PC" in the left bottom

3-Click on "Troubleshoot" and then the Advanced Options page will appear.

4-Click on "Command Prompt".

5-Run these commands.

Diskpart

List Disk

List Vol

6-Take a photo of the result of these commands and attach it here

You can see at this link how to include a screenshot in your post.

https://answers.microsoft.com/en-us/feedback/fo...

Answer 3

Hey, RobinsonSilvestre

Thanks for quick response. Already done all these steps.

Actual issue is Boot Manger not working with EFI (Non CSM).

_________________

When selected in BIOS
CMS: Yes

BIOS Mode: EFI --or-- BIOS Mode: Legacy
Works fine and boot the MBR installation flash or already installed Windows 10.
_________________
When selected in BIOS
CSM: No
BISO Mode: EFI
Doesn't boot EFI (Non CSM) installation flash stay at boot manager screen.

_________________

Answer 4

I was unaware about the problems if once the EFI partition is deleted this is going very hard task to install windows EFI (non CSM) again.

Spent hours of reading and practical but no success in installing windows EFI.

When I select in my BIOS EFI (non CSM) the boot manger stuck with a dialogue displaying 2 disks (flashdriver + system disk) all we can do is press 'Tab' and select Enter Setup.

Window 10 MBR booting fine.

Following is system information:

BIOS Mode Legacy

Had the computer ever had a BIOS UEFI / GPT Windows installation that booted without problems or were the prior installations BIOS Legacy / MBR?

Please post images or share links displaying BIOS options:

Legacy

UEFI native (without CSM)

UEFI hybrid (with CSM)

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Installing UEFI or EFI windows 10 is much complicated if once EFI partition deleted.

4 answers