Windows 10: Windows can't access UEFI after converting to BIOS and Disk gets Invalid

Summarized - I was trying to install Windows 24H2 on my old Acer Aspire V5-571P, which previously installed Windows 11 23H2 smoothly. However, I'm now encountering "operating system not found" errors. I've tried using Ventoy to create a bootable USB, changing BIOS settings from UEFI to Legacy, and enabling various options, but nothing works. I can't access BIOS and all repair options fail. Command prompt shows my disk 0 as invalid and dynamic. My next step is to install Ubuntu and then dual boot with Windows 11. Any help would be appreciated.Complete - I attempted to install Windows 24H2 on my

:)

 

Convert Windows 10 from Legacy BIOS to UEFI without Data Loss  


Here it is:

 

Convert BIOS to Uefi

It's not possible to "convert from BIOS to UEFI" if UEFI was not built into the hardware. Your laptop is an older model that probably pre-dates common use of UEFI.

 

Windows 10 - Converting BIOS to UEFI

Hello. I have the current version of Windows 10 and a motherboard that supports UEFI, but is currently using BIOS. I want to convert from BIOS to UEFI. I understand that there are two main processes involved. Changing the HDD from MBR to GPT and changing
the motherboard settings from BIOS to UEFI. I was going to use the recently available Microsoft tool MBR2GPT.EXE, however a Microsoft article states the tool cannot be used if a disk has more than three partitions. Mine for some reason has two system reserved
partitions. One is shown as F: System Reserved , capacity is 100MB, used space is 31.89MB and the status is "none". The other one is shown as *: System Reserved, capacity is 100MB, used space is 30.83MB and the status is "system". I have a System partition
(C and a Data partition (D.

I would like to know how I can convert BIOS to UEFI without losing my data or having to re-install Windows 10. All advice will be appreciated.