Convert from MBR to GPT issue

You cannot convert MBR disk to GPT which contains partitions.

Check article : https://technet.microsoft.com/en-us/library/cc725671.aspx

You can change a disk from MBR to GPT partition style as long as the disk does not contain any partitions or volumes.

You can use thirdparty partitioning tools to convert disk from MBR to GPT.
Ref : http://www.partitionwizard.com/convertpartition/convert-mbr-to-gpt-without-data-loss-windows-7.html

NOTE : If you convert disk containing system partition, your system will not boot.

Hi Sir,

Thank you for reverting.

I have one Healthy (OEM Partition), RECOVERY - Healthy (System, Active, Primary Partition) and OS (C) Healthy (Boot, Page File, Crash Dump, Primary Partition). When I right click them it the Delete volume is unable to select, only shrink volume is available. And can I check with you which one is able to remove? When I uses cmd list disk only 0 appear which is mean I have one partition? Kindly correct me if I am wrong.


Thanks

list disk   shows you the physical drives
what you need to do is
list disk
select disk 0
list partition

converting a mbr boot to a uefi boot means losing everything on the disk..
to delete partitions that are special partitions you have to use the override parameter
select partition 3
delete partition override

"You cannot delete the system partition, boot partition, or any partition that contains the active paging file or crash dump (memory dump) file"  Which means you have to do it form a boot disk and not the O/S

What specific reasonining do you want to move from MBR to GPT disk? For most people it doesn't make sense.

Hi Sir,

Thank you for reverting back.

I want to use UEFI window 10, currently windows 7 legacy, is require gpt disk to install it. I don't know is I deleted this few partition will cause my pc to crash. Kindly advice.

Thank!

Hi Sir,

Thank you for reverting back,

I have just bought a dell optiplex 5040, I wanted to upgrade to windows 10 using the CD given but it doesn't install windows 10 and instead ask for me to choose the language, keyboard and lastly troubleshoot or turn off your pc. The dell win 10 os cd given to me written " Already installed on your computer" but it's windows 7, that is very weird.  I had set the boot option to UEFI and untick/tick enable legacy option roms, secure boot off and on, and yet still unable to install load window 10 from the cd. I had contract dell live chat and they had no idea thus like to check if anyone know about dell uefi boot. Alot said must set GPT to make it boot to uefi, but I am afraid deleted this 3 default partition will cause my pc to crash. Any help will be appreciate.

Thanks

Yes, sure it will crash and make your PC unbootable. You can download full version of Windows 10 ISO and install it from it. If you have Windows key of course.
Why at all do you want to have it UEFI? You can upgrade your Windows 7 to Windows 10 directly. Through updates like explained here: http://www.windowscentral.com/how-to-upgrade-windows-7-windows-10
Check here as well how to upgrade it: https://www.microsoft.com/en-us/windows/windows-10-upgrade

from windows 7 insert the disk and select upgrade.  If you boot useing efi then it requires that the disk be gpt or it won't install. if you boot from mbr it won't install to a gpt disk

Thank to all the help