[hazqeel]

according to this article
https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10
Although disks configured with MBR-style partition can have up to four primary partitions, for this process to work the disk you want to convert can't have more than three partitions, because one allocation is needed to create the new UEFI system partition

for MBRtoGPT disk need to have only 3 partition but in my disk i got 4 C, D, E and system reserved. Can i delete only E for convertion to GPT or i need to format complete disk?

[TechFreak1]

according to this article
https://www.windowscentral.com/how-c...efi-windows-10
Although disks configured with MBR-style partition can have up to four primary partitions, for this process to work the disk you want to convert can't have more than three partitions, because one allocation is needed to create the new UEFI system partition

for MBRtoGPT disk need to have only 3 partition but in my disk i got 4 C, D, E and system reserved. Can i delete only E for convertion to GPT or i need to format complete disk?

If you have a laptop, I would recommend getting a new hdd / ssd and also use the free version of magical jellybean keyfinder to obtain your windows 10 key as you will need it if you have not attached a microsoft account to Windows 10 and using a local user with selective app sign-in.

GPT and MBR cannot be used consecutively on the same hard drive / ssd therefore the easiest method is to wipe the entire drive or get a new hdd / ssd and create a GPT Windows 10 installation.

By default the media creation tool will create a MBR install, unless you are running Windows 10 on GPT.

The best tool to use is Rufus.

rufus.akeo.ie

Download the Windows 10 ISO from Microsoft and use this tool to create a GPT install.

[hazqeel]

i bought new HDD and installed windows 10 with GPT but how i am going to use my old HDD and what about all my data on it

[neo158]

You need to make sure that the system you have has UEFI or the OS won't boot from a GPT volume.

[hazqeel]

old hdd is MBR and new ssd is GPT it is working fine without any issue. all my data is ok.