Windows 10: Something changed SSD format from GPT to MBR

Updated from W10 1508 to the anniversary edition early this year - 250gb SSD as main drive, and system clone on a 750gb SSD/HDD hybrid, both GPT format. After a month or so the OS on the SSD crashed, and I could not re-load W10. Was told that the drive was formatted MBR. Switched to the clone, everything was ok for about three weeks, then it crashed. Same problem. Reformatted both back to GPT, loaded W10 1703 onto the SSD, now running with no problems. Still to do the clone.
Does anyone have any idea what could have caused this? I have only found one similar reference on the net, and that involved W7.
I have on two occasions had the UEFI/BIOS corrupted, but being a dual BIOS board, have been able to recover that. No corruption problems in this case though.

:)

 

Benefits of UEFI/GPT boot disk vs. MBR for Windows 10

Hi

I just upgraded to Windows 10 Home 64bit from Windows 7 Home Premium 64bit that was installed on MBR formatted 250MB SSD. As I'd like to create bootable copy on USB and do a clean install of Windows 10 I was wondering whether I should keep using MBR format
or Windows 10 would actually benefit more from GPT formatted SSD. My Asus Maximus VII Hero motherboard comes with UEFI BIOS. So are there any benefits of using GPT format for Windows 10 vs. MBR format or will I potentially cause more problems managing and
troubleshooting system with GPT drive? And then what format should I use for my 1TB HDD where I keep my data?

Appreciate any advice.

Thanks

 

Update to Windows 10 Creator 1709 always fails.

Problem solved

Hard drive (Micron SSD) was formatted as GPT originally by Windows 7. Converted to MBR now in my despair with AOMEI 6.6 without losing data.

Creator went on without problem.

I still do not know why and how this was a problem.

GPT worked well apparently with previous Win10 versions.

Creator installed on freshly GPT formatted ssd drives if I tried fresh install on other computers at home.

BIOS is UEFI so should work with GPT without problem as it used to do.

May have had some corrupt partition table or something, will never find out.

 

Your clone image must be of an mbr based install. Some bioses will run uefi or legacy bios mode automatically - others you have to specifically select mode.

 

Cerebus,
Started thinking about that after I posted, and yes, probably didn't reformat the hybrid to GPT.
However, what could have happened to the SSD? It was in GPT format before the first W10 install, otherwise it could not have loaded. W10 worked fine for a year. Could a mobo bug or virus have changed the SSD format? Kaspersky could not shed any light on this possibility. MOBO BIOS is set to select UEFI or Legacy automatically.

 

I don't know what changed it but if it's running you can do this: Convert Windows 10 from Legacy BIOS to UEFI without Data Loss Windows 10 Installation Upgrade Tutorials
I did it just couple of weeks ago when switching from legacy to UEFI mode.

 

There is no way a mobo bug could change a drive from gpt to mbr. Even if a virus changed your drive to mbr, it is hardly going to do that without losing all data.

I am betting your first install that you backed up was an mbr install. If you are using pro, you could load the Macrium image file you made as a vm using viboot and look at partitions and that will tell you if it backed up an mbr install.

 

Cerebus,
As stated, SSD was GPT format [BIOS in UEFI], when W 10 v1508 was first installed, v1607 and anniversary update also went onto that drive, the cloned hybrid drive [v1607] was probably MBR. I lost all data with both crashes. Most was backed up, so I only lost about 3 weeks worth of emails. In both these instances, I was using the computer, everything was fine, then suddenly just a black screen.
You've lost me in the second paragraph after you reached 'Macrium'. *sarc Am using W10 Home Premium x64.

CountMike
v1703 currently running happily on the reformatted GPT SSD, BIOS still UEFI, so probably not much point in using your suggestion at the moment.
Regards,