Windows 10: No bootable device no partition is active after change from legacy BIOS to UEFI

This happened after I made some BIOS setting changes from within Windows 10 (my mistake), in order to prepare my laptop to begin booting with UEFI mode. I have the latest OS. I get no options for UEFI in my BIOS setup, nor is the system partition active. It is coded as being uefi. When I try to change to active using command line, it errors that the active command won't work on that partition, because it's not an mbr.

:)

 

Install Windows 10 using UEFI bootable USB thumb drive

You need to go into you system bios and select allow uefi usb drive. Then add the UEFI usb drive to the boot menu

better way to partition aand create an bootable usb.

For the UEFI system, we can use these steps to create the bootable USB:

1.Locate a 4GB or larger USB flash drive

2.Open Diskpart and run the following command cmd admin type diskpart

• Type DiskPart in the command prompt.
• Type "List Disk” (make note of the disk number of the target USB drive).
• Type "Select Disk X”, where X is the target USB drive noted in step 4.
• Type "Clean”.
• Type "Create Partition Primary”.
• Type "format FS=fat32 quick”.
• Type "Active”.
• Type "Assign".
• Type "Exit".

Copy your ISO files to the drive and reboot

never use UEFI it better to repartition and remove UEFI go with legacy bois

 

Problem Regarding Bios Change from UEFI to Legacy

I have hp pavilion p045tx with windows 10 pro. I recently install Ubuntu with windows 10 so for that I convert my bios setting from UEFI to Legacy mode for install third party software like wireless Driver and all in Ubuntu.
But after every restart the bios setting change to default and that is to UEFI mode and that will cause an problem of no OS detect. Every time I have to go to bios setting and enable the legacy mode to start my OS. Can anyone suggest me what to do in this
case.

 

What determines how a fresh installation of Windows onto a fresh hard drive chooses whether to use UEFI or legacy BIOS

Hi Michael,

Basically if Secure Boot is turned on, Windows must be installed onto a GPT system and the installation will create a UEFI partition on that drive

If Secure Buut is disabled and Legacy BIOS is used, the installation will be like all the old Windows installations, installed onto an MBR disc and no UEFI partition

To install in Legacy BIOS Mode:

Insert the Bootable Installation Media, then go into your BIOS and make the following changes:

1. Disable Secure Boot

2. Enable Legacy Boot

3. If Available enable CSM

4. If Required enable USB Boot

5. Move the device with the bootable disc to the top of the boot order

6. Save BIOS changes, restart your System and it should boot from the Installation Media