Windows 10: Boot not available because both startup disks seen as MBR format

I just updated my PC with new Win11 compatible motherboard, after much work in the bios got Win10 to load, then installed new SSD and copied the system to it. after again fiddling with the Bios could boot from either disk by using app easy cd. But something I did now will not let me boot into either disk. I get a message somewhere that both disks are now try to use MBR rather than GPT. I don't have a recovery Cd but have a recovery backup on a WD external drive but cannot or is not found on restart. What are my options please?

:)

 

How To Format A Write Protected Flash Memory ?

¿You already tried this one?...

Run CMD


1. diskpart
2. list disk

Then in the 3º step, put the correct number of disk in the list for the usb flash (if it's listed in disk 3, then you'll have to write select disk 3).

2. select disk #
3. clean
4. create partition primary
5. select partition 1
6. active
7. format fs=fat32
8. assign
9. exit

with that commands you will format the flash drive in fat32, if you have a large drive you can select also "format fs=ntfs" in step 7.

good luck!

 

Expand Recovery Partition and Enable Windows RE with MBR Disk

Thanks all for the help. The recovery environment is working correctly. I tried the ReagentC command boottore last night on the MBR system and the system did boot into the recovery environment. In regards to my original question on the sequence of steps, is it necessary to delete the expanded recovery partition first and then create the new one as suggested in the Microsoft instructions? I believe I just did the quick format and set ID=27 for the MBR disk.

 

clone MBR HD to bootable GPT partition?

Hi,

1. You cannot convert mbr to gpt without data loss. otherwise, you can follow directions here:

FROM WINDOWS RECOVERY CONSOLE:

To change a master boot record disk into a GUID partition table disk using a command line

• 
  Back up or move the data on the basic master boot record (MBR) disk you want to convert into a GUID partition table (GPT) disk.
  
• 
  Open an elevated command prompt (right-click Command Prompt, and then click Run as Administrator) and type diskpart. If the disk does not contain any partitions or volumes, skip to step 6.
  
• 
  At the DISKPART prompt, type list disk. Make note of the disk number you want to convert.
  
• 
  At the DISKPART prompt, type select disk <disknumber>.
  
• 
  At the DISKPART prompt, type clean.
  

2. I'd suggest converting your vista drive to a virtual machine, load that up on your windows 10 system and use a program like virtualbox to run it.