Q:

Convert MBR to GPT - Without any OS

I just got a new laptop without any OS (it had FreeDOS, but not anymore). When I go to Windows Installer and try to create a new partition from un-allocated space, I don't get any Error message but the installer is unable to create the partition. At the bottom of the installer window, there's a warning which says something like,

Windows cannot install on MBR *partition. On EFI systems, Windows can only install on GPT *partition

How can I convert MBR to GPT *partition without any OS?
*I am not sure if it was partition or not

A:

This is easy, when you go through installation guide, you can at any time press Shift + F10 - command prompt shows up. 
Then write Diskpart, then List Disk. You see there a list of your disks, then select the one you want to convert.
Select disk 0 (if you want to install on the first disk, for an example).  Clean it with Clean, and convert into GPT Convert GPT. Enjoy
Unluckily I wanna MBR and got GPT :/

A:

You should be able to do this with a live distro of GParted I believe.
This is a fairly generic tool which allows a number of operations to be performed on drives whilst booted up from a USB stick or CD-ROM

