Windows 10: Windows 10 will not boot, No disk found after converting disk

Converted primary/Dynamic Disk0 where I have c drive with windows 10pro from mbr to gpt on my 2 year old DELL notebook after removing 2 logical partition and kept 3 pri.ary partitions. So all I have were 4 primary partitions. One has system restore two are system partitions. After that I changed the boot record from legacy mode to GFEI. when I boot, I get the message no bookable disk. As the original hard drive was replaced, windows 10 pro was installed on MBR partition. Is there any way to bring the notebook back to life?

:)

 

Converting a MBR disk to a GPT disk

I would put Windows on Disk 2. There is plenty of space. If you want to start with a clean slate then you should do this:

• Disconnect disks 0 and 1.
• Boot the machine with your installation medium.
• Launch diskpart.
• Select disk 0 (it was disk 2 before).
• clean.
• Reboot with your installation medium.
• Install Windows.
• When it runs nicely, connect the other disks and tell the BIOS which is the primary disk to boot from.

Since disk 2 is only 232 GBytes you will not need UEFI / GPT. After Windows is installed you can convert the 3 TByte disk to GPT.

 

Convert GPT Disk to MBR Disk in Windows 10


Recently I met an occasion where a Win10 installation on a GPT disk needed to be converted to MBR.
I think my experience may be of some help.

The target system was Win10 Enterprise, installed on an empty 300GB HD. The layout (as reported by "diskpart") was :
Code:

Code:

 Volume ###  Ltr  Label        Fs     Type        Size     Status     Info   ----------  ---  -----------  -----  ----------  -------  ---------  --------   Volume 1     C                NTFS   Partition    297 GB  Healthy    Boot   Volume 2         Recovery     NTFS   Partition    450 MB  Healthy    Hidden   Volume 3                      FAT32  Partition     99 MB  Healthy    System

Basically I followed "OPTION ONE" of Shawn Brink (the author of the original post).
Steps 1-3 were straightforward.
After clicking "Convert GPT Disk to MBR Disk" in Step 3, a warning poped out :





Click "OK" to dismiss, then proceed to Step 4.
After clicking "Apply", another warning appeared soon :





Click "Restart Now" to proceed.
The restart triggered the conversion before loading the OS.
When the conversion was completed (in just one or two minutes), the system was restarted again.
But this time it CRASHED : some error message saying OS not found.

This is normal, because the conversion tool did not mark the system partition as "bootable".
Now :

1. Boot the target system with the Win10 installation media (DVD/USB etc).
2. Select language & click the "Next" button.
3. Click the "Repair your computer" link.
4. Click the "Troubleshoot" square.
5. Click the "Command Prompt" square.
6. At the command prompt, invoke the "diskpart" tool.
   • Locate the target partition by using the "select" and "list" commands.
   • Execute the "select partition x" command, where x is the target partition number.
   • Execute the "active" command to mark it as "bootable".
   • "exit" the "diskpart" tool.
7. "exit" the command prompt.
8. Click the "Startup Repair" square. The system will restart after the repair.
9. Done.

After the fix, the layout of the target disk looked like :
Code:

Code:

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info    ----------  ---  -----------  -----  ----------  -------  ---------  --------    Volume 1                             Partition    450 MB  Healthy    Offline    Volume 2                             Partition     99 MB  Healthy    Offline    Volume 3     C                NTFS   Partition    297 GB  Healthy    System

Finally, a couple of remarks :

• The time required for the "Startup Repair" step varies on different systems. For the 300GB disk mentioned above, it was finished in less than a minute. On another case with 1TB HD, it took nearly 3 hours of heavy disk read-write to complete the operation.
• One downside of the method is worth notice : almost all of the functions in "Advanced startup" ("Start" -> "Settings" -> "Update & security" -> "Recovery" -> "Advanced startup") were gone after the conversion.

 

Convert Basic Disk into Dynamic Disk

Hi Charbel,

It would be helpful if you mentioned the things that you have tried to do that failed so that we can skip those steps. You can follow the steps provided in the article:
How to convert a basic disk to a dynamic disk in Windows 7, to change a basic disk to
a dynamic one. The instructions are also applicable for Windows 10. You can also check this article:
Extend a basic volume.

Ensure that you create a back up for your system as well.

Regards.