Windows 10: GPT - UEFI problem, reinstall required?

Hi guys,

New to the forum, thanks for the help you provided in the past *Biggrin
Hope you can help as my PC is now inaccessible.

Yesterday I installed the new MB and CPU/RAM. Everything was fine, I started Windows, installed chipset drivers (moved from Intel to AMD), checked disks status etc.

After that, I decided to convert the OS disk from MBR to GPT for UEFI bios compatibility. Started MBR2GPT with /validate command (ok) and then launched the conversion.
Restarted the pc, switched BIOS from Legacy to UEFI and restarted Windows 10but.. BSOD A Required Device Isn't Connected or Can't Be Accessed error Code: 0xc000000e.

Since then, I tried several solutions in order to solve the issue, no chance. In particular:

- BIOS switch from UEFI to Legacy
- Launched the system from a bootable usb media (windows 10) for Startup repair tool, no way. The error cannot be solved by the tool
- Command prompt for the bootrec /fixmbr etc. commands, no change
- Command prompt, CHDSK /R, no change. SFC /Scannow cannot be performed due to Windows protection settings
- Windows 10 re-install via usb. Custom install (files and folders deletion), the process seems to complete successfully and the system restarts. Same error. I cant install Windows on the secondary disk as it is a dynamic disk.

The disk is in good health (checked with Crystaldiskinfo) and it worked fine before the conversion.
I was wonder to clone the C: disk into an external drive via command prompt and then clean all the partitions on C: in order to re-install Windows again. Is that feasible?

Any ideas?
Windows version is 2004 (latest updates). Sorry for not providing any log but I cannot retrieve it from Windows.

:)

 

Problem switching to GPT

No probs with the partition. I already did it (see my post) but never crossed my mind that UEFI did not require GPT as I thought GPT was part of the UEFI spec. Please post the steps and point me to your source.
Thanks

 

install using gpt, uefi required?!?


The real answer is sort of .. on a Legacy boot, you can initialize the drive as GPT and you can dism install Windows
BUT... you lose recovery (and possibly more things) - the hidden/backup MBR in GPT drives isn't the same as a true MBR.

I suggest using an extended partition and logical drives on a Legacy boot system.
3 Primary parts, one Extended part(with as many logical drives as you deem needed).

I'd have to see your Disk Management to advise further.

Step 1: Download this zip file (contains dmDskmgr-vd.mmc)

dmDskmgr-vd.zip
Step 2: Double click dmDskmgr-vd.zip to open the compressed folder
Double click dmDskmgr-vd.mmc to launch the custom Disk Management console
You'll get an output similar to this:




Press Alt+PrtScn to grab a snapshot of just the Disk Management window
Open Paint and Ctrl+V to paste it, then save the image
Attach the image to a new post.
Option 2: Use Disk Management in the x-Menu (right click the Windows logo, select Disk Management)
Select View > Bottom > Disk list
Maximize the window and grab the screen shot.

 

Convert Windows 10 MBR to GPT (UEFI)?

In reviewing my Windows 10 Pro (64-bit) system I noted that the Secure Boot Status is showing as "unsupported". Investigating further, it appears either the GPT partition for booting using UEFI (is Secure Boot) has become corrupt or my installation was
never installed for Secure Boot. My Windows 10 install is an auto-upgrade from a Windows 8.1 install.

Is there a way to convert the MBR to GPT without doing a fresh install? I do have a USB recovery drive built at a point I believe I had indications Windows was booting from a GPT (UEFI) partition. In fact, the USB recovery drive shows as being a UEFI drive.

Any suggestions will be appreciated!

Thanks!