Does it boot from GPT?

[hpatricia]

Hello!

Simply put, I would like to know if I can format my laptop's disk (from which the laptop will boot) in gpt.

Context:

I need to create several partitions in my disk, and with MBR I have a maximum of 4.  (Formating the  disk in gpt is just one of the option for my problem, the other being the use of extended partitions, but here I just want to debate the gpt issue).

However, I have been told that not all pcs are able to boot from a gpt disk, and that it will depend on the controller supporting UEFI, or something like that. I don't really understand the issue, even after reading articles about MBR, GPT, BIOS and UEFI. So if anyone would be so kind as to explain all that, it would be appreciated!

The disk is unbootable at the moment, so I can't check system files (as I have seen in some tutorials that explain how to find out if the pc supports UEFI).

Not sure if this helps, but, on the startup menu of the machine:

System info > Current System BIOS version: M71 Ver. 01.18.

System Diagnostics > HP PC Hardware Diagnostics UEFI: Version 1.6.1.0 - BIOS

Thank you!

[Huffer]

Your computer will have no problem booting from a GPT disk. It is a 5th gen Intel Core processor. If it is currently MBR, you have to remove all existing partitions and convert to gpt:

https://technet.microsoft.com/en-us/library/cc725671(v=ws.11).aspx

Is this your OS disk or another one? 

[hpatricia]

Thank you for your reply.

Yes, the disk I want to convert to gpt is the one with the OS (I tried to say that by calling it the 'boot disk').

But if you don't mind me asking, why does that have to do with the processor? That's the part I would like to understand, if I can convert it, then why, how could I know that?

[Huffer · Accepted solution]

It has nothing to do with the processor directly but that is a new processor (relatively) and therefore supported by a chipset that fully supports secure boot and UEFI. If you had a Pentium 4 I would tell you to forget it. You cannot directly convert from MBR to GPT without loss of data. 

[hpatricia]

Ok, thank you. As to the convertion, I already have to format the whole disk anyway. I suppose that windows instalation setup will ask me if I want gpt or mbr?

[Huffer]

Strip all the partitions out of the drive until it is all unallocated space and Windows 10 installer will make it GPT