Help with GPT Conversion.

fruman23 · 28 Aug 2021 at 17:49

Of course it's another issues with windows 11 thread!

I've converted my main win 10 boot drive to GPT using 3rd party software, but when I boot to windows after changing to UEFI in my bios it's throwing an I/O error with a .efi file.

Anyone in the know as to how i can get it booting again? I've cloned the drive so not worried about data loss, but would be much easier to upgrade from 10-11 than a fresh install for me.

Cheers

Uhtred · 28 Aug 2021 at 20:52

Is there a reason you used 3rd party software to do the conversion? mbr2gpt.exe is built into the OS

fruman23 · 28 Aug 2021 at 22:28

I tried that a few months back and ironically ran into the same issue as I’m facing now.

Uhtred · 28 Aug 2021 at 23:05

Sounds like you're missing the 100mb partition. There's a good guide here to create one http://woshub.com/how-to-repair-deleted-efi-partition-in-windows-7/

It says windows 7 but I suspect it will work fine. After that's done you will need to do some bcd magic to get the new partition working.

fruman23 · 29 Aug 2021 at 14:34

I've had a scout at that link, tried everything with still no luck, even with a clean install, maybe just not destined to get it to work!

Thanks though, much appreciated

Kautya · 29 Aug 2021 at 21:20

Uhtred said:
Is there a reason you used 3rd party software to do the conversion? mbr2gpt.exe is built into the OS

I had used this in the past when I was facing the same issue. Was very easy, if you search you would find an easy tutorial for this.

No 4 on this article - https://www.easeus.com/partition-ma...-mbr-using-cmd-without-losing-data.html#part3